President Donald Trump remains commander in chief for only more 10 weeks, until President-elect Joe Biden takes office in January. But during that time, Trump is in a position to make destabilising foreign policy choices that could sow chaos and tie Biden’s hands.

While the president has been raging on Twitter about an election he sees as illegitimate, his administration is rapidly exerting control over key national security positions – elevating the risk of mayhem and alarming experienced officials across Washington, DC.

On Monday, Trump fired defence secretary Mike Esper, removing one of the key officials who have, to some degree, pushed back against the president’s plans. He replaced Esper with Christopher Miller, the former head of the National Counterterrorism Center, who is known for encouraging the US to more aggressively confront Iran, which Trump allies want to pressure before the president leaves office.

A series of further personnel moves at the Pentagon followed. Top defence officials resigned and were replaced by Trump loyalists, including Anthony Tata, who has called former President Barack Obama a “terrorist leader” and has pushed a range of unhinged conspiracy theories, and Republican operatives Kash Patel and Ezra Cohen-Watnick.

“It is hard to overstate just how dangerous high-level turnover at the Department of Defence is during a period of presidential transition,” House armed services committee chairman Adam Smith said on Tuesday.

And at the National Security Agency, Trump installed Michael Ellis, who was previously involved in Republican efforts to question Russian interference in the 2016 election, as general counsel, according to The Washington Post. Ellis has been transferred to a civil servant position, making it harder for Biden to remove him, CNN reported.

The president is desperate to declassify intelligence on Moscow’s meddling to justify his 2016 win, regardless of how that might hurt sensitive research methods and American alliances, the Post reported on Wednesday.

Experts and Democratic operatives said the risk of vengeful or irresponsible moves by Trump is particularly high when it comes to foreign policy, an area in which the president can often act unilaterally. 

“The only thing that has kept Donald Trump from doing things that would have been absolutely crazy, and I would underscore absolutely, was the prospect of reelection and political pressure,” said a former Obama administration official who requested anonymity to speak frankly. In a transition period, “The limited guardrails that have been on this presidency would no longer be there.”

“We would see this president take precipitous action in ways that would be counter to our national interest but then would also set in motion crises that the Biden administration would have to account for,” the former official added.

The possibilities worrying the ex-Obama staffer and others range from Trump launching a war, to using an executive order he signed last month to place political loyalists in some influential roles usually held by civil servants.

And the personnel moves in the national security arena go well beyond just the Pentagon and National Security Agency. It’s clear a thorough purge is underway. On Friday, Trump ousted Bonnie Glick, a former foreign service officer serving as the deputy head of the sprawling US Agency for International Development. The move kept his controversial appointee John Barsa in charge of the organisation, despite the fact that his term as acting chief has expired. On Monday, Barsa told his team the transition of power to Biden has not yet begun, CNBC reported. 

Trump also forced Lisa Gordon-Hagerty, the administrator of the agency that oversees America’s nuclear stockpile, out of her job on Friday. “That the secretary of energy effectively demanded her resignation during this time of uncertainty demonstrates he doesn’t know what he’s doing in national security matters,” Senator Jim Inhofe, the chair of the Senate armed services committee, said.

Trump’s general services administration chief, Emily Murphy, has also refused to sign a letter granting resources to Biden’s transition team, the Post reported on Sunday night, subverting a normal practice seemingly because of the president’s dishonest claims that the election is still not settled. That denies Biden not only taxpayer funding and computer systems but also full intelligence briefings, which former House intelligence committee chairman Mike Rogers, a Republican, said the president-elect should already be receiving.

A longtime Trump adviser told HuffPost he believes that CIA director Gina Haspel and FBI director Christopher Wray could also be removed soon.

Biden’s team can’t do much to rein Trump in. They want to respect the fact that the Us only has one president at a time – not least because of Democratic frustration with Trump acting as though he was already in charge when dealing with Russia, Israel and the United Arab Emirates before Obama left office in 2016. They also know the country will already be tense as Trump pursues lawsuits to deny Biden’s victory and baselessly alleges election fraud; they don’t want more squabbling that undermines Americans’ and foreigners’ faith in the US commitment to an orderly and peaceful transition of power.

Few Democrats expect help from Republicans. Many Republican lawmakers are already promoting Trump’s dangerous conspiracy theories about the vote. Even when opposition figures have challenged the president’s foreign policy choices, they have rarely actually blocked them. And some ambitious Republicans clearly want to stay on the Trump family’s good side, anticipating that the outgoing president will remain a force in conservative politics.

“I don’t have any faith in Mitch McConnell’s Senate. As we’ve all seen over the last four years, the president has a lot of flexibility and leeway when it comes to national security, so I’m not really sure there are many guardrails,” the former Obama staffer said.

Asha Rangappa, a former FBI official, predicted upcoming “sabotage, vindictiveness, and norm-breaking” beyond even the excesses of Trump’s first term. “It’s time to brace ourselves,” she tweeted on Sunday.

What is Trump trying to achieve? 

Iran will likely be Trump’s biggest target in his lame-duck period. 

Hardliners in the administration believe Democrats are too soft on Iran and want to make it difficult for Biden to resurrect the Obama-era accord that gave Iran greater access to the global economy in exchange for limits on its nuclear programme. Some figures associated with Trump’s maximalist Iran policy, notably secretary of state Mike Pompeo, also believe pushing a hard line now could help them if they seek higher office later.

On Sunday, American news site Axios reported that Trump plans to “flood” Iran with sanctions. The country of 80 million is already struggling under unprecedented US restrictions and one of the world’s worst outbreaks of the coronavirus. A new wave of financial pain would boost anger and distrust on the Iranian side and eventually set up a tougher fight for Biden domestically, where he would have to justify rolling back those measures to a hawkish Congress.

Trump could also create a situation that’s so difficult Iran feels it must respond or – as some Pentagon officials worry – launch his own operations, including in secret. 

The administration has already proved willing to risk a direct clash by hitting Iran-linked targets in Iraq, notably Iranian commander Qassem Soleimani, the former Obama official noted. “We could certainly see more of that and even on an accelerated scale if this president isn’t bound by any sort of political pressure.”

Iran is also thought to still want to avenge Soleimani’s killing and some analysts believe it could use the unstable transition period to do so. Tehran may avoid a confrontation, however, in preparation for a more coherent approach from Biden, said Tamara Cofman Wittes, a former state department official now at the Brookings Institution.

Transition teams like Biden’s and career officials at agencies like the Pentagon are familiar with the risks of these periods, she added, citing past instances of North Korean escalations around the time of US elections. 

Meanwhile, anti-war advocates are prepared to check the president, particularly if he frames a rush to war as part of his broader attempt to cling to power.

“If Trump escalates with Iran, it will be a ruse to try to shore up his support and further try to invalidate the elections. [He] could view a conflict with Iran as a means towards assaulting US democracy more than he has already,” Yasmine Taeb of Demand Progress wrote in an email. “The American people and progressives should be hyper cautious, be ready to organise, and view any claims Trump and company make about Iran with the utmost scrutiny.”

What does this mean for the US?

America enters the transition with a severely weakened professional foreign policy apparatus.

The state department (which oversees foreign affairs) “is decimated and demoralised,” Wittes said, citing Trump’s attacks on career diplomats who have exposed actions like his bullying of Ukraine for the sake of his political vendetta against Biden. “It’s going to take a huge amount of work to come back from that damage.”

Before the president-elect can begin that work, Trump can cause additional pain. His October executive order on federal employees makes it easier for him to fire career civil servants and fill positions without going through the normal competitive hiring processes.

“How many more talented, knowledgeable experts is the US national security bureaucracy going to lose? That’s putting a new administration behind the eight ball,” Wittes said. (Congress could legislate to curtail Trump’s powers under the order, she said, but is extremely unlikely to do so.)

Trump can also change the contours of international politics, limiting Biden’s flexibility to restore traditional American positions or advance progressive priorities.

The president is already advancing plans to sell major new weapons systems to the United Arab Emirates and, potentially, its rival Qatar, and he could further weaken America’s limits on treating occupied Palestinian territory as part of Israel. As he plans for a post-presidency future in which he has to pay back hundreds of millions of dollars in debt, Trump could cut quid-pro-quo arrangements with the cast of international leaders who have benefited from his transactional style and worry they will be able to get less out of the U.S. under Biden. 

“This is changing the dynamics and it’s done recklessly,” Wittes said.

In Afghanistan, it’s possible Trump will carry out the rushed troop withdrawal he has pledged for months, over concerns from Esper and others – a move the president could claim as a legacy item, thrilling conservatives, but one that could also quickly cause bloodshed, gains for terror groups, and, eventually, a messy return for US troops. That would make it impossible for Biden to pursue the more deliberate drawdown he has promised.

He could “undermine our remaining interests there, potentially causing a Biden administration to do things that no one would want to do,” the former Obama official said.

Can Biden stop him?

The Biden team’s commitment to a standard pre-Trump transition process is unlikely to waver, even as sitting officials make parts of that impossible.

“The ability to coordinate with foreign governments is not going to be on the table,” for instance, the former Obama official said – even if Trump ratchets up insults against counterparts abroad or makes promises they might expect Biden to keep.

The hope is that public positions can, well, trump private assurances and the last gasps of the Trump era.

Wittes, the former diplomat, said Biden can send clear signals with choices like which international officials he engages with, as congratulatory calls and messages come in. On Monday, the transition team confirmed that he spoke with Canadian prime minister Justin Trudeau in his first call with a future counterpart. Most recent presidents have made the US’s northern ally the destination for their first foreign trip. Trump instead went to Saudi Arabia.

And while Democrats see the risk of Trump appointees remaining in government to try and undermine the next administration, they feel the practice – known as “burrowing” – may not be as corrosive as it might have been during past transitions.

“What distinguishes Trump appointees is they don’t have a public service bone in their bodies. They’re there because of their loyalty to President Trump; once he’s gone, their inclination to remain, even to thwart a Biden administration, I don’t think will be that powerful for a lot of these people,” the ex-Obama staffer said, suggesting they are far more likely to seek lucrative private sector work.

The Biden team, meanwhile, has a huge number of national security professionals it wants to bring in and has been quietly conducting advance work to do so quickly.

Whatever Trump does in the weeks ahead, he can’t erase the sense of a ticking clock that’s set in in Washington and internationally.

“The rest of the world knows that they have President Trump for the next 80 or so days but then after that, they know that they will be dealing with a President Biden,” the former Obama official said.