One month on from U.S. President Donald Trump’s last-minute non-bombing of Iran, tensions in the Persian Gulf have escalated even further and his administration’s strategy for dealing with Iran is less clear than ever.

Trump now faces critical challenges within his own party and his own administration to both sides of the carrot-and-stick dynamic he hopes will achieve a nuclear and ballistic missile-neutered Iran: military force and negotiations with Tehran.

Confidence at home in Trump’s leadership on Iran suffered a major bipartisan rebuke this month, when the U.S. House of Representatives passed legislation to block Trump from waging war with Iran without Congressional approval.

Republican leaders in the Senate, who are likely to kill the amendment (repeating a similar effort in June), slammed the move as signalling to Tehran that the United States is divided. They fear that could potentially weaken Trump’s position in any future negotiations with Iran.

Meanwhile, the list of hostile incidents between Iran and the U.S. and its allies is lengthening. Iran seized two British oil tankers in the Gulf, eventually releasing one, a day after Trump said the U.S. destroyed an Iranian drone in the Gulf - a claim that Tehran immediately denied. In June, Iran shot down a U.S. Navy drone in the same area.

Open gallery view Iranian Revolutionary Guard speedboat of moving around the British-flagged oil tanker Stena Impero seized in the Strait of Hormuz on Friday. July 21, 2019 Credit: Morteza Akhoondi,AP

That act prompted Trump to authorize a military strike on Iran, only to call it off at the last moment, despite being, in his own words, "cocked and loaded" - because the estimated death toll of 150 Iranians was "not proportionate to shooting down an unmanned drone."

Critics derided Trump’s hesitation to take action as analogous to former President Barack Obama’s inaction after Syria’s Bashar Assad crossed the president’s much-hyped "red line" and used chemical weapons against civilians and opposition forces.

Trump is being squeezed between his bombastic rhetoric, having vowed to "end Iran" if they attack the U.S. or its allies in the region, and his lack of action in response to serial Iranian aggression.

Trump’s plan, as far as it can be surmised, is to threaten with a stick - military action - while offering to negotiate - his carrot - but without clear preconditions at all, apart from wanting any new accords to halt Iran’s now resurgent nuclear program to be superior to Obama’s "worst deal ever."

As Trump inimitably put it: "Iran is in big trouble right now. A lot of bad things are happening to them. It’s very easy to straighten out, or it’s very easy for us to make it a lot worse."

But with Iran currently breaching the deal by enriching uranium beyond the permitted limits, Trump put himself in the awkward position of both calling for Iran to comply with the "terrible" deal he withdrew from, and asking Iran to return to the negotiating table - the same table Trump slammed Obama for offering in the first place, and to negotiate a deal which would be highly likely to resemble Obama’s.

Trump has scored one minor victory: Iran has offered, for the first time, to enter negotiations on its ballistic missile program. However, they are demanding a quid pro quo that Trump would be loathe to offer: a commitment from the U.S. to stop selling weapons to Saudi Arabia and the UAE - a policy which has been roundly rebuked by both Democrats and Republicans in Congress because of their use in the devastating civil war in Yemen.

Trump has also been playing around with the officials tasked with the Iran file. At the end of last week, Trump confirmed that he gave Republican Senator Rand Paul, a staunch isolationist, a green light to negotiate with Iran.

Open gallery view U.S. Senator Rand Paul (R-KY) walks into the Capitol in Washington, U.S., May 21, 2019 Credit: \ JAMES LAWLER DUGGAN/ REUTERS

Paul, son of libertarian lion Ron Paul, is a strange character to add to the White House mix deciding Iran policy: both National Security Adviser John Bolton and Secretary of State Mike Pompeo are known as longtime Iran hawks. Bolton once even penned a New York Times op-ed entitled, "To Stop Iran’s Bomb, Bomb Iran."

As news broke of Paul’s involvement, Trump waffled, "I would listen to him, but I didn’t appoint him, no..No, he’s somebody I listen to, and I respect Sen. Paul, and if he had some ideas I would listen."

The very next day, Paul was more or less back in the hot seat and Trump clarified his role, saying he’d "asked me if he could get involved. The answer is yes...I have many people involved, and Iran is going to work out very nicely."

Rand Paul is one of four GOP Senators who voted in June for legislation to check Trump’s ability to order a strike on Iran. That attempt failed. Trump’s latest inclusion of Paul on his Iran team - if that appointment has any bite - seems to, further diminish the role of Bolton, a veteran foreign policy operative and the most prominent anti-Iran hawk in the Trump White House.

But that put-down of Bolton is part and parcel of Trump apparently playing off different voices - or perhaps, another sign that he’s influenced by the last person he spoke to. This time, it may have been Tucker Carlson.

Carlson had viciously denounced Bolton in the aftermath of Trump’s aborted strike on Iran; he was, reportedly, central in convincing Trump to show restraint.

Carlson argued that Trump would risk his reelection prospects by bombing Iran and potentially starting a third simultaneous U.S. conflict in the Middle East.

Trump, in 2016, ran on an anti-war platform lambasting George W. Bush and his "stupid" wars in Iraq and Afghanistan and promising the U.S. wouldn’t get involved in any more wasteful adventures in the Mideast - that "very rich" countries like Saudi Arabia should pay for their own defense.

Open gallery view U.S. National Security Adviser John Bolton stand before a press conference in Jerusalem, Tuesday, June 25, 2019 Credit: Oded Balilty,AP

Trump’s appointment of Bolton, Bush’s former UN ambassador and an architect of the Iraq war, was a surprise to many in his base and is now red meat for both Democrats and Republicans alike who are pushing to end the U.S.’s "forever wars." The quasi-appointment of Rand Paul is a move towards that anti-war base.

Bolton has been fingered as the prime mover to force the UK, a crucial U.S. ally on Iran, to be drawn in "unambiguously" on America’s side in the oil tanker wars, setting London up as "collateral damage." That was intended to be a way for Bolton to forcefully rope in the incoming UK Prime Minister Boris Johnson to his hawkish camp, despite Johnson having publicly committed to not follow Trump into a war with Iran.

Iran’s Twitter-savvy Foreign Minister Javad Zarif was quick to pile on the Bolton criticism: "Having failed to lure @realDonaldTrump into War of the Century, and fearing collapse of his #B_Team, @AmbJohnBolton is turning his venom against the UK in hopes of dragging it into a quagmire."

Trump is clearly keenly aware that, ahead of 2020, despite his ongoing attempts to tie the Democratic Party to Ilhan Omar and Alexandria Ocasio-Cortez, he too is vulnerable if he’s too closely tied to hawks like Bolton.

An opinion poll taken June 22-23 found that a full 50 percent of Republicans wanted a peaceful solution after Iran shot down the U.S. drone, while 67 percent of Democrats wanted negotiations or no response and 54 percent of independents said the same.

A different survey of swing state voters, taken around the same time, found 83 percent of respondents wanted "the same or lower levels of foreign military engagement by the U.S."

Paul last week somewhat preeningly responded to hawkish Lindsey Graham on Twitter, after all three had shared a round of golf with Trump:

"Proud that @realDonaldTrump and I argued with you against endless wars! @POTUS made it clear to all of us at the table, we are getting out of the Middle East quagmire. We’ve been there too long. Time to bring our troops home."

But it’s not just his base that’s attempting, at least symbolically, to handcuff Trump’s capacity to really threaten Iran with sustained military force: Congress and several Democratic presidential candidates are putting up stiff resistance as well.

Placing effective checks on the executive’s ability to wage "endless wars" is certain to be a major campaign issue for both parties, not least because it’s the wildly inconsistent Trump who holds the reins of power.

Trump’s lack of a confirmed defense secretary since Jim Mattis’ dramatic resignation in December, days after Trump announced a sudden withdrawal from Syria, adds more fuel to calls for greater oversight over an executive branch already operating beyond its Constitutional bounds in terms of war powers and managing the military.

It’s also an issue that creates unlikely bedfellows, bringing together the Democrat’s progressive left and the GOP hard right. That marriage of convenience was clear in the House anti-war powers legislation, co-sponsored by close Trump ally Rep. Matt Gaetz and by Democrat Ro Khanna.

The call to limit Trump’s freedom of movement on Iran may well influence which candidate wins the Democratic nomination.

Open gallery view Democratic U.S. 2020 presidential candidates Pete Buttigieg, Joe Biden, Bernie Sanders, Kamala Harris, Kirsten Gillibrand and Michael Bennet at the second candidates debate. Miami, June 27, 2019 Credit: \ Carlo Allegri/ REUTERS

2020 Democratic candidates like Senator Bernie Sanders, Senator Elizabeth Warren, Hawaii Congresswoman Tulsi Gabbard and Massachusetts Congressman Seth Moulton have set out with an avowedly anti-war, anti-interventionist message.

And the pushback against Trump’s capacity to strike Iran is not only coming from the harder left. Centrist Democratic presidential candidates Joe Biden and Pete Buttigeig have also vowed to stop those "endless wars."

Buttigeig joined in calls for a full repeal of the war authorization passed by Congress in the wake of Sept. 11, which gave the president legal authority to use all "necessary and appropriate force" against its perpetrators and any forces thought to be associated with them. A repeal did pass the House in June, but has since stalled in the Senate.

Despite all this legislative activity, the president’s war powers are still ascendant.

Despite the U.S. Constitution only granting Congress the power to declare war, and the War Powers Act of 1973 that sought to constrain presidents entering prolonged conflicts without approval from Congress - from Obama in Libya to Clinton in Somalia - U.S. presidents have continued to make war or support foreign war efforts without congressional approval.

The Bush-era post-9/11 authorization has been used as a blank check ever since for the U.S. to fight terrorism overseas. With the Gaetz-Khanna legislation, Congress may have tried to performatively dent Trump’s ability to attack Iran under the 2001 authorization to fight al-Qaida-related terrorism, but Trump still has presidential workarounds.

But the cumulative effect of all these obstacles, most notably the hostility of his base to military intervention, means Trump seems all but certain to avoid a major escalation.

In doing so, his threats become more like shadow boxing, Iran gains the upper hand and the U.S. is left only with Nixon’s "madman" approach to negotiating - the hope that Iran, when push comes to shove, will be bowed by fear or Trump’s unpredictability and potential for extreme military action.

Trump has boxed himself in between establishment GOP hawks and a growing, more isolationist faction within the party. The divide between Rand Paul and John Bolton, or Tucker Carlson and Mike Pompeo, perfectly illustrates that when it comes to war/no war with Iran, none of Trump’s choices are good choices. None will bolster his credibility with all wings of the GOP, his White House staff or the international community, which is watching with mounting concern.