TRUMP’S NATO VISIT: After his 30-minute private audience with Pope Francis at the Vatican today, President Trump departs Rome for Belgium and his much anticipated appearance at NATO, an alliance that Trump once disparaged as obsolete, but more recently praised for embracing the reforms he has advocated. In a nod to the U.S. president, the 28 member nations (soon to be 29 with the addition of Montenegro) are expected to renew a pledge they made a few years ago to spend at least 2 percent of their gross domestic product on their own defense by 2024. The nations committed to the goal in 2014, but now they are expected to show how they will meet it in the seven remaining years. Only five countries are currently in compliance: Britain, Poland, Greece, Estonia and the United States. And the U.S. spends more than all the other allies combined.

A number of announcements have been saved for the big NATO leaders summit, including an expectation that NATO will formally join the 68-nation international coalition fighting the Islamic State, a move heavy with symbolism, coming as it does after ISIS claimed responsibility for Monday’s deadly suicide bombing in Manchester, England.

And NATO may also commit more military trainers to Afghanistan, just two and half years after NATO “combat” troops were withdrawn at the end of 2014, when the now almost 16-year-long war was declared officially over. The U.S. is prepared to send several thousand additional special operations forces to train more Afghan commandos to break what U.S. commanders have described as a “stalemate.” But the U.S. wants NATO to step up as well. Last week, Defense Secretary Jim Mattis said he done all the consulting and groundwork, but has not yet made his formal recommendation to Trump.

The president will also get a look at NATO’s spiffy new billion dollar headquarters, set to fully open later this year.

The elephant in the room will be what do about Turkey, whose President Recep Tayyip Erdogan just met with Trump at the White House, and whose government has moved away from the West, and increasingly toward authoritarianism and suppression of dissent and press freedom. One example was an ugly display last week during Erdogan’s visit, when his security forces beat peaceful protesters outside the Turkish ambassador’s residence in Washington. Erdogan also has purged around 11,000 military personnel from its armed forces since last year's unsuccessful coup, including hundreds of senior officers who were removed from posts at NATO.

Mattis leaves for Brussels today to join Trump at tomorrow’s summit. Mattis is traveling without any news media on his plane, since he is not the principal at this meeting, so we don’t expect and readout of comments he made en route. As one of his aides said, “There is always the possibility he will bump into a reporter,” but no press events are planned.

UK TERROR THREAT CRITICAL: British Prime Minister Theresa May has raised the terror alert status in the UK to critical, and deployed armed troops to patrol the streets, after the Islamic State claimed a member of the terror group carried out the deadly attack in Manchester, according to SITE Intelligence Group, Melissa Quinn writes. ISIS said "a soldier of the Khilafah managed to place explosive devices in the midst of the gatherings of the Crusaders in the British city of Manchester," according to the statement, tweeted by SITE. "The explosive devices were detonated in the shameless concert arena," the ISIS statement said. "And what comes next will be more severe on the worshipers of the Cross and their allies."

May convened an emergency meeting of her cabinet, as British authorities work to determine whether the bomber, 22-year-old Salman Abedi, a British citizen, was part of a network that may be planning further attacks,

BUT THE U.S. ISN’T SURE YET: American intelligence sources have not yet independently verified that the Islamic State is responsible for Monday night's attack that killed 22. “It's a tragic situation that we see all too much of happening in countries around the world," Director of National Intelligence Dan Coats said yesterday, adding that while ISIS has claimed responsibility, “They claim responsibility for virtually every attack, we have not verified yet the connection."

Good Wednesday morning and welcome to Jamie McIntyre’s Daily on Defense, compiled by Washington Examiner National Security Senior Writer Jamie McIntyre ( @jamiejmcintyre), National Security Writer Travis J. Tritten ( @travis_tritten) and Senior Editor David Brown ( @dave_brown24). Email us here for tips, suggestions, calendar items and anything else. If a friend sent this to you and you’d like to sign up, click here. If signing up doesn’t work, shoot us an email and we’ll add you to our list. And be sure to follow us on Twitter @dailyondefense.

YOU HEARD IT HERE FIRST: Sometime in the near future you will hear an announcement of a upcoming test of America’s national missile shield, the system of radars and ground based interceptors that are designed to track and destroy an incoming warhead from a hostile nation, such as North Korea, while it’s still in space. The test will be portrayed by many in the news media as a direct response from the Trump administration to the increasingly bellicose and threatening missile and nuclear tests. It’s certainly true that the test, especially if it succeeds, will send a message to Pyongyang, but the fact is the test has been in the works for years, according to Pentagon officials.

The U.S. has not tested its ground-based system since 2014, when nothing went right, and the system failed to shoot a dummy warhead. Since then, many changes have been made to software computer codes and hundreds of computer simulations have been run, and confidence is running high that this test will succeed, say officials familiar with the preparations.

EXPANDING THE SHIELD: A bipartisan group of senators wants the government to explore how to expand United States missile defense systems to a new realm: space, Joel Gehrke writes. "We're in unique times, and we need to explore all means of protecting ourselves," Sen. Brian Schatz told the Washington Examiner.

Schatz is one of the most liberal members of the Senate, but the looming threat of North Korean dictator Kim Jong Un's nuclear weapons program has prompted him to collaborate with Alaska Republican Dan Sullivan and six other senators across the ideological spectrum on a broad missile defense bill. Their proposal calls for "the development and deployment of a space-based sensor layer" to aid 28 new ground-based interceptors in detecting and downing incoming ballistic missile attacks.

TRUMP BUDGET PANNED: Nobody on Capitol Hill seems much impressed with Trump’s $4.1 trillion fiscal 2018 budget request, with its $639.1 billion for the Defense Department ($574.5 billion base, plus $64.6 billion for overseas contingency operations). Sen. John McCain set the tone declaring the budget, “dead on arrival in Congress,” as well as “inadequate to the challenges we face” and “illegal under current law.” McCain was referring to the fact the proposed Pentagon spending plan exceeds the caps imposed by the Budget Control Act of 2011.

“We absolutely, essentially need to reverse defense sequestration,” John Roth acting Pentagon comptroller said at yesterday’s Pentagon rollout of the defense budget. “We must increase the defense budget caps in order to support financial security strategy and any new defense strategy as well,” Roth said. But one problem is the Trump plan offers no way to break the congressional gridlock that so far has kept the budget caps in place.

“Even though his request would violate the Budget Control Act, the President has presented no plan to solve this problem through the repeal of sequestration, despite his party controlling both houses of Congress and the Presidency,” said Democratic Rep. Adam Smith, ranking member on the House Armed Services Committee. Smith also complained about Trump’s failure to submit a five-year “Future Years Defense Program,” known as the “FYDP.” “His budget omits long-term planning assumptions that are needed to make sober and strategic choices about national security,” Smith said.

We pored over the budget yesterday, and listened to hours of mind-numbing briefings so you didn’t have to, and assembled the highlights in a special edition of Daily on Defense that went out last night. Check your inbox, or click this link for easy access.

HAPPENING TODAY: The war against the Islamic State is mostly being fought on the ground, but it is the air power of the U.S. and its coalition partners that has been the decisive factor on the battlefield. We’ll get an update on the air war today from Air Force Lt. Gen. Jeffrey Harrigian, commander, U.S. Air Forces Central Command. He’ll brief Pentagon reporters live from Baghdad this morning. Yesterday, Pentagon spokesman Navy Capt. Jeff Davis said roughly 90 percent of Mosul has been freed of the grip of ISIS, and that the remaining fighters were completely surrounded in a small area of the old city in west Mosul.

THE BIGGER THREAT: Trump's top intelligence adviser condemned the spate of leaks that have bedeviled his administration as a threat to national security on Tuesday, while saying he won't comment on reports that the president asked him to tamp down reports of collusion between the campaign and Russia, Joel Gehrke writes.

"Lives are at stake in many instances and leaks jeopardize those lives," Dan Coats, the director of national intelligence, told McCain during a Senate Armed Services Committee hearing on worldwide threats. Coats applied that principle to his own conversations with the president. The former Indiana senator refused to confirm a Washington Post report that Trump asked him and NSA Director Mike Rogers to make a public statement that there is no evidence of collusion between Russia and the Trump presidential campaign.

“Is that an accurate reporting, Director Coats?” McCain asked.

“I have always believed that given the nature of my position and the information in which we share is not appropriate for me to comment publicly on any of that. And so, on this topic, as well as other topics, I don't feel it's appropriate to characterize discussions and conversations with the president,” Coats replied.

Democratic Sen. Jack Reed tried a different approach. “Hypothetically, if a president reached out to the director of national security and made such a request, would you think that would be appropriate?” Reed asked.

“Any political shaping of that presentation or intelligence would not be appropriate,” Coats answered. “I have made my position clear on that to this administration and I intend to maintain that position.”

THE RUSSIAN CONNECTION: Former CIA Director John Brennan told Congress yesterday how the whole FBI investigation of possible Trump campaign collusion with Russia got started last summer. Brennan said he saw information dealing with contacts between Russia and the Trump associates that was "worthy" of further investigation, Todd Shepherd writes.

But Brennan, citing the need to protect classified information, declined to describe what he saw, or to say whether he thinks the information showed that Trump's team was colluding with Russia. "Did you see evidence of collusion, coordination, conspiracy between Donald Trump and Russian state actors?" Rep. Trey Gowdy asked Brennan.

"I was aware of intelligence and information about contacts between Russian officials and U.S. persons that raised concerns in my mind about whether or not those individuals were cooperating with the Russians, either in a witting or unwitting fashion, and it served as the basis for the FBI investigation to determine whether such collusion, cooperation occurred,” Brennan, testified before the House Intelligence Committee.

The White House response: “This morning’s hearings back up what we’ve been saying all along: that despite a year of investigation, there is still no evidence of any Russia-Trump campaign collusion.”

THE FLYNN PURSUIT: The top two members of the Senate Intelligence Committee said all options are "on the table" when it comes to determining how to proceed against Mike Flynn, who invoked his Fifth Amendment rights and refused to turn over subpoenaed documents, Todd Shepherd writes. That includes issuing new subpoenas not to Flynn, but to Flynn's business, according to Committee Chairman Richard Burr and Vice Chairman Mark Warner.

Speaking moments after a closed-door meeting was finished, Warner said the committee is now subpoenaing documents from two of the former national security adviser’s businesses, and the committee will argue that corporations cannot be shielded by the Fifth Amendment.

LEVERAGE OVER THE SAUDIS: Trump's $110 billion weapons deal with Saudi Arabia could have an unannounced side benefit of giving the United States leverage to reduce the Muslim monarchy's support for radical clerics, according to Republican lawmakers. "There's no doubt there are things the Saudis are going to have to do to improve on as well," Sen. Marco Rubio, R-Fla., told Joel Gehrke.

There are signs Trump is aware that the deal could help him address the problem. Just last year, candidate Trump was accusing Saudi Arabia of funding terrorism. A veto-proof majority of Congress voted last fall to allow the victims of the 9/11 attacks to sue the Saudi Arabian government, and the Saudis were criticized heavily for financing schools around the world that teach a fundamentalist variant of Islam known as Wahhabism. "That's the issue, in addition to other human rights concerns and other things," Rep. Peter Roskam said of the Wahhabist schools. "It's the incendiary, it's the kindling."

BUT PAUL HAS A DIFFERENT PLAN: Sen. Rand Paul will attempt to force a Senate vote on the arms deal, according to Senate staff. The Republican Kentucky senator could file a motion on the vote either Tuesday or Wednesday.

A Senate vote could throw the massive decade-long deal with the Saudis into uncertainty after the Trump administration touted it as new evidence of a tight alliance.

CAN WE MAKE A DEAL? While in Israel, Trump said be believes a peace deal with the Palestinians is possible, and said he would continue working with both sides to reach what he admitted is an elusive goal, Alex Pappas writes. "Making peace, however, will not be easy," Trump said during a speech at the Israel Museum alongside Israeli Prime Minister Benjamin Netanyahu, and expressed a similar sentiment after his meeting with Palestinian Authority President Mahmoud Abbas.

“I am committed to trying to achieve a peace agreement between the Israelis and the Palestinians and I intend to do everything I can to help them achieve that goal. President Abbas assures me he is ready to work toward that goal in good faith. And Prime Minister Netanyahu has promised the same,” Trump said. “I look forward to working with these leaders toward a lasting peace.”

GREAT MEETING? OR GREATEST EVER? During a joint appearance with Abbas, Trump also offered this assessment of his meeting in Saudi Arabia with King Salman, who he called a “very wise, wise man.”

“It was a deeply productive meeting. People have said there has really never been anything even close in history. I believe that. Being there and seeing who was there and hearing the spirit and a lot of love — there has never been anything like that in history,” Trump said. “And it was an honor to be involved. But great things can come from that meeting.”

WHAT WAS ALL THAT “SMART COOKIE” TALK? Trump told Philippines President Rodrigo Duterte in a telephone call last month he believed North Korean dictator Kim Jong Un was a "madman with nuclear weapons," according to a transcript of the call cited by the Washington Post last night. The Post reported that Trump asked Duterte whether he believed the North Korean leader was "stable or not stable."

The private rebuke of Kim took place three days before Trump publicly said he would be "honored" to meet him. Duterte, who had led a deadly crackdown of drug addicts and dealers, had told Trump the North Korean was "playing with his bombs, his toys," adding "his mind is not working well and he just might go crazy one moment."

THE RUNDOWN

BuzzFeed : Thousands of people attend emotional vigil to honour those killed in Manchester Terror Attack

Reuters : U.S. starts 'extreme vetting' at Australia's offshore detention centers

Defense One: Trump’s first defense budget has North Korea written all over it

New York Times: Democrats warn Trump against pre-emptive attack on North Korea

Defense Tech: Navy looks to replenish Tomahawk stockpile after Syria, Yemen strikes

USNI News: Pentagon requests just 1 littoral combat ship in FY 2018 budget despite Navy’s industrial base concerns

Defense & Aerospace Report: F-35 Lightning II PEO Bogdan on Trump’s Impact on Lot 10 Contract Negotiations

War on the Rocks: Three things the Army chief of staff wants you to know

Reuters: South Korea fires at suspected drone at border with North amid missile crisis

DoD Buzz: Air Force kills retirement date for U-2 spy plane

USA Today: The U.S. blew up a huge stash of ISIS cash

Foreign Policy: At odds with Trump, Nikki Haley charts her own foreign policy path

Wall Street Journal: Philippines declares martial law on southern island

Defense News: Dual hatted: Navy crew train up on manned and unmanned helos

Calendar

WEDNESDAY | MAY 24

1800 Jefferson Davis Hwy. Breakfast keynote by Vice Adm. Terry Benedict, director of the Navy’s Strategic Systems Programs. navyleague.org

9:30 a.m. Russell 232-A. Industry perspectives from Brian Cuccias of Huntington Ingalls, John Casey of General Dynamics, and Matthew Paxton, president of the Shipbuilders Council Of America, on options and considerations for achieving a 355-ship Navy. armed-services.senate.gov

9:30 a.m. Rayburn 2154. Oversight of the FBI’s independence. oversight.house.gov

10 a.m. House 140. Testimony from Gen. Joseph Lengyel, commander of the National Guard Bureau, and the chiefs of the reserve military forces. appropriations.house.gov

10 a.m. 1616 Rhode Island Ave. NW. The Russian military of 2035. csis.org

10 a.m. Dirksen 342. Border insecurity with the rise of MS-13 and other transnational criminal organizations. hsgac.senate.gov

10:30 a.m. Dirksen 192. Review of the 2018 budget for the Navy and Marine Corps with acting Navy Secretary Sean Stackley and Adm. John Richardson, chief of naval operations. Appropriations.senate.gov

11 a.m. Pentagon Briefing Room: Air Force Lt. Gen. Jeffrey Harrigian, commander, U.S. Air Forces Central Command, briefs the media live from Baghdad on counter ISIS air campaign.

11 a.m. 1211 Connecticut Ave. NW. Examining the strategic implications of Trump’s first budget. stimson.org

12 p.m. 214 Massachusetts Ave. NE. The threats and challenges of the South Caucasus region for the Trump administration. heritage.org

2 p.m. Rayburn 2212. Navy fiscal 2018 budget request for seapower and projection forces. armedservices.house.gov

2 p.m. Hart 216. The Kremlin's gas games in Europe and the implications for policy makers, with Sen. Jeanne Shaheen. atlanticcouncil.org

2 p.m. Rayburn 2172. Nuclear deal fallout and the global threat of Iran. foreignaffairs.house.gov

2:30 p.m. Dirksen G-50. Department of Energy atomic defense activities and programs with Frank Klotz, undersecretary for nuclear security. armed-services.senate.gov

3:30 p.m. Rayburn 2118. Ground force modernization budget request with Army and Marine Corps officials. armedservices.house.gov

THURSDAY | MAY 25

8 a.m. Rayburn 2212. Air Force FY 2018 budget request for seapower and projection forces with Lt. Gen. Arnold Bunch, Lt. Gen. Jerry Harris and Lt. Gen. Mark Nowland. armedservices.house.gov

8 a.m. 300 1st St. SE. A discussion about nuclear modernization and strategic stability with Gen. Stephen Wilson, Air Force vice chief of staff. mitchellaerospacepower.org

8 a.m. 7940 Jones Branch Dr. OPNAV N4 Supply Chain Risk workshop. ndia.org

9 a.m. 1030 15th St. NW. Report launch on why Africa matters to U.S. national security. atlanticcouncil.org

9 a.m. 1616 Rhode Island Ave. NW. Countering Coercion in Maritime Asia with Adm. John Richardson, the chief of naval operations. csis.org

9 a.m. 1300 Pennsylvania Ave. NW. Rep. Adam Kinzinger about the way forward in Afghanistan, America’s longest war. wilsoncenter.org

9:30 a.m. Dirksen G-50. Posture of the Army with Gen. Mark Milley. armed-service.senate.gov

10 a.m. Rayburn 2118. Fiscal 2018 priorities for nuclear forces and atomic energy defense with Gen. Robin Rand, commander of Air Force Global Strike Command, and Vice Adm. Terry Benedict, director of Navy Strategic Systems Program. armedservices.house.gov

10:30 a.m. Dirksen 138. Review of the 2018 budget request for the Department of Homeland Security with Secretary John Kelly. appropriations.senate.gov

TUESDAY | MAY 30

5:30 p.m. 1789 Massachusetts Ave. NW. The future of Iranian power in the Middle East with Lt. Gen. Thomas J. Trask, U.S. Special Operations Command, and retired Vice Adm. Mark Fox. aei.org

WEDNESDAY | MAY 31

8 a.m. 1700 Army Navy Dr. Defense leaders forum breakfast with Lt. Gen. Joseph Anderson. ndia.org