THE CLOCK IS TICKING: The countdown to a military strike on Syria is underway, and the only question seems to be whether the U.S. will act alone — as it did a year ago — or in concert with allies Britain and France. British media is reporting that Prime Minister Theresa May is under heavy pressure to join the U.S., perhaps by contributing Tomahawk cruise missiles from one of its Astute- or Trafalgar-class submarines.

President Trump spoke to both May and French President Emmanuel Macron Sunday, the day after the suspected chemical weapons attack in Douma, but before he had received military options from the Pentagon. The Times of London reports members of May’s government are warning that Britain risks losing influence in Washington and Paris if it turns down Trump’s request to join a retaliatory strike. “President Macron of France was said by Whitehall sources to be ‘egging on’ Mr. Trump,” the paper reports this morning. “They acknowledged that Downing Street had been left embarrassed as Mrs. May was still waiting to speak to Mr. Trump last night.”

In the past, Macron has called the use of chemical weapons by the regime of Bashar Assad a “red line” and has repeatedly threatened to strike chemical weapons sites in Syria if they were used again.

A MENU OF OPTIONS: As you would expect, the president has been given a range of options, Pentagon officials confirmed to me yesterday, including another Tomahawk cruise missile strike. Like last April’s strike, a volley of Tomahawks would minimize any risk to U.S. pilots posed by Syrian or Russian air defenses. “While the process of drawing up and presenting the options are similar to last year, I wouldn’t look at this through a soda straw,” said one Pentagon official familiar with the planning. “It’s up to the president to decide how to respond. It’s up to us to provide the options.”

A Navy source said the U.S. has a number of ships armed with Tomahawk cruise missiles in the region, including the USS Donald Cook, a guided-missile destroyer that has just completed a port call in Cyprus, and is now in the eastern Mediterranean within range of Syria.

“We have a lot of options militarily, and we'll be letting you know pretty soon. Probably after the fact,” Trump said yesterday as he prepared to sit down for a dinner session with his senior military leaders. Earlier in the day at a meeting with the emir of Qatar at the Pentagon, Defense Secretary Jim Mattis told reporters “I don’t rule out anything right now.”

‘THE US WILL RESPOND’: Trump has left little doubt he plans to act soon. “I will not say because I don't like talking about timing,” he said last night. But he vowed, “It will be met, and it will be met forcefully.”

It’s a position that U.S. Ambassador Nikki Haley underscored at an emergency briefing at the United Nations yesterday. “We are beyond showing pictures of dead babies. We are beyond appeals to conscience. We have reached the moment when the world must see justice done. History will record this as the moment when the Security Council either discharged its duty or demonstrated its utter and complete failure to protect the people of Syria,” Haley said at the session. “Either way, the United States will respond.”

PUTIN WILL PAY: Trump didn’t shy away from pointing an accusing finger at Russian President Vladimir Putin, who was supposed to have guaranteed that Syria had no more chemical weapons. Asked by reporters at the White House if Putin bears responsibility for the attack on civilians, Trump said, “He may. Yeah, he may. And, if he does, it's going to be very tough. Very tough. … Everybody's going to pay a price. He will, everybody will.”

BLOOD ON THEIR HANDS: At the heated U.N. session, Haley was even more unsparing in her criticism of Russia, which she accused of “shielding a monster” in propping up Assad. “Russia and Iran have military advisers at Assad’s airfields and operations centers. Russian officials are on the ground helping direct the regime’s ‘starve and surrender’ campaign, and Iranian allied forces do much of the dirty work. When the Syrian military pummels civilians, they rely on the military hardware given by Russia,” Haley said. “The Russian regime, whose hands are all covered in the blood of Syrian children, cannot be shamed by pictures of its victims. We’ve tried that before.”

FAKE NEWS: Russia continues to claim that the reports of a chemical attack on civilians in Syria are “fake news” staged by the rebels, and is calling for an international investigation that it insists will find no evidence to support the accounts.

At the U.N., Russia’s ambassador continued to warn against military intervention. “Armed force under mendacious pretext against Syria, where, at the request of the legitimate government of a country, Russian troops have been deployed, could lead to grave repercussions," said Vassily Nebenzia. “From what we hear now, I am afraid they are looking for a military option, which is very, very dangerous.”

SYRIA EXIT STRATEGY UNAFFECTED: White House press secretary Sarah Sanders insists there is a “separation” between Trump's desire to withdraw U.S. troops from Syria after the Islamic State is defeated, and his planned response to the Syrian government's alleged use of chemical weapons. "The president has made clear that with the defeat of ISIS, he wanted to be able to bring our troops home," Sanders told reporters at the White House. "But at the same time, he wants to make sure Assad is deterred from chemical weapons attacks on innocent civilians."

Good Tuesday 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.