One hour before Donald Trump left office, he quietly tried to secure one of the bloodiest parts of his legacy: funneling American weapons to Middle Eastern dictators committing war crimes and human rights abuses. As Americas political elite gathered for Joe Bidens inauguration, officials from the United Arab Emirates signed agreements to buy $23 billion in U.S. weaponry an arms deal that nearly all Democratic senators had voted to stop weeks earlier.

The weapons sale, Trumps largest, would make the Emirates one of a handful of countries to own the top-of-the-line F-35 fighter jet and give Abu Dhabi its first American-armed drones, as well as associated bombs and missiles. Its a multiyear project that would drastically change the balance of power in the volatile Persian Gulf. Supporters say that would benefit the U.S. by deterring adversaries like Iran, but critics believe the move will create fresh tension in the region, worsen the UAEs already brutal military interventions and expose American technology to China and Russia.

Biden halted the transfer one week into his tenure by placing it under review. It seemed like an early win for progressive legislators and activists who want Washington to stop fueling Middle East conflicts and hope the president will deliver on his campaign promises to build a more restrained U.S. foreign policy.

But its still unclear whether the pause in the arms deal will prove temporary. Despite Bidens pledge to end the war in Yemen, which the UAE is helping drive, and his freeze on more than $750 million in sales of bombs to the Emirates close ally Saudi Arabia, Biden could ultimately permit Trumps deal.

That choice would track with the United States history of overlooking horrifying behavior by its friends a tradition that many Biden administration appointees have publicly described as making the world more dangerous for Americans by fueling resentment abroad. It would thrill autocrats who fear that Trumps departure will mean consequences for their violations of international norms. And it would undermine the Democratic-aligned effort to make American foreign policy more humane.

It wouldnt be entirely surprising, however.

In late 2016, President Barack Obamas national security team pledged to review American support for the bombing campaign that the Saudis and the Emiratis were running in Yemen, after an airstrike on a funeral killed nearly 150 people. The Obama aides most of whom are back in power under Biden ultimately declined to end the policy, only partially reducing assistance.

Trump then restored and expanded that support. U.S.-linked bombs claimed thousands more civilian lives and Yemens humanitarian situation became more desperate. Meanwhile, former Obama staffers blasted Trump for a policy that they established and failed to end.

As the Obama-Biden circle considers how to use its power this time around, hawks outside the administration are trying to box them in by treating the deal as a fait accompli and arguing that tweaking or canceling it would be an insult that threatens the Emirates recent decision to establish diplomatic ties with U.S. ally Israel. Yousef Al Otaiba, the UAEs high-profile ambassador in Washington , told a Feb. 1 conference that the review was simply pro forma and the process of completing the transfer was ongoing.

Bidens decision expected in April will show how far hell go to resist Americas militaristic impulses and learn from Obamas mistakes.

Leading figures in the debate over Washingtons approach to global affairs say his review must be significant and ambitious to the extent that it might tank the billion-dollar deal.

Trump sought to rush through sales of our most advanced fighter jet and most lethal armed drone technology to the United Arab Emirates bypassing congressional consultation and leaving many more questions than answers, Sen. Chris Murphy (D-Conn.) told HuffPost. The UAE is an important security partner and we have reasons to work together. But we must have a serious debate about if the Middle East is going to be a safer place with Reaper drones, which the U.S. has never before sold into the region.

He noted the UAEs recent track record: growing close to China and Russia, funneling weapons into Libya despite an international arms embargo and providing American arms to abusive militias in Yemen.

Im glad that President Biden is reviewing this sale so we can get some answers and make more nuanced decisions that will ultimately leave the United States in a safer place, Murphy, who chairs the Middle East panel on the powerful Senate Foreign Relations Committee, said. This should be part of our larger strategy to reset the U.S. relationships across the Gulf to make sure they align with our national security interests.

Erica Fein, the advocacy director at Win Without War, told HuffPost that many activists believe ending the weapons sales and accounting for the damage the Emiratis and the Saudis have done to Yemen with previous U.S. support is now a test of Bidens credibility.

Until that happens, we will keep pushing to end the culture of impunity for this war and demand an end to arms sales to Saudi Arabia and the UAE, she said.

The Art Of The Review

Close observers of Bidens team do not expect them to double down on the policies of Trump and Obama.

Theres space now to make major, dramatic change unlike in the last two or three administrations, said Daniel Mahanty, a former State Department official who is now at the Center for Civilians in Conflict.

During the Obama administration, the officials conducting the review that ultimately maintained U.S. support for the Saudi-UAE intervention reached their final decision after Trump had won the 2016 presidential election. HuffPost understands that they felt a limited reprimand would not be immediately reversed by the incoming president and would create at least some pressure on the U.S. partners to end the war.

The first goal was arguably achieved: The Saudis did not receive new U.S. bomb shipments for six months. The second clearly was not: The two U.S. partners ramped up their vicious campaign.

Mahanty believes Obama shied away from a serious adjustment for three reasons: because the U.S. is so addicted to arms sales that the government struggles to unwind them; because officials at the time still felt U.S. assistance could make change for the better in Arab partners behavior; and because the president prioritized his nuclear deal with Iran a project the Saudis and Emiratis could make more difficult.

Five years and many civilian deaths later including in Libya, where U.S. intelligence last year blamed the UAE for a major war crime Bidens team could think very differently.