US President Donald Trump has announced that the United States will send an additional 5,000 troops to Poland, a surprise move that has deepened uncertainty about Washington’s military posture in Europe.

In a post on his Truth Social platform on Thursday, Trump linked the decision directly to his relationship with Poland’s right-wing President Karol Nawrocki.

“Based on the successful Election of the now President ⁠of Poland, Karol Nawrocki, who I was proud to Endorse, and our relationship with him, I am pleased to announce that the United States will be sending an additional 5,000 Troops to Poland,” Trump wrote.

But the move comes just days after the Pentagon cancelled the deployment of about 4,000 troops to Poland as part of a wider reduction of US forces in Europe.

The abrupt reversal has fuelled questions about what exactly Trump has ordered – and whether the deployment is driven by military strategy with Europe, or by the US president’s increasingly transactional approach to alliances.

What has Trump ordered and which troops are involved?

While Trump described the move as a new deployment, reports from US media suggest the announcement may actually amount to a reversal of an earlier Pentagon decision.

Last week, the Pentagon abruptly halted the deployment of the 2nd Armored Brigade Combat Team of the 1st Cavalry Division – a Texas-based unit of more than 4,000 troops that had been preparing to rotate into Poland and Eastern Europe.

According to The Wall Street Journal, Trump later questioned Defense Secretary Pete Hegseth about why the deployment had been cancelled, telling him the US should not “treat Poland poorly” given its close ties to Washington.

Several reports said some parts of the brigade – known as the “Black Jack Brigade” – had already begun moving equipment and personnel when the deployment was stopped.

The Pentagon has not confirmed whether Trump’s newly announced 5,000 troops are the same soldiers whose deployment was cancelled earlier this month, or whether they will be redeployed from elsewhere in Europe, such as from Germany.

The White House and Pentagon have so far released few other details about this latest deployment.

Poland currently hosts about 10,000 US troops, largely on a rotational basis, according to the Polish government. Since Russia’s full-scale invasion of Ukraine, the country has become one of Washington’s most important military partners on NATO’s eastern edge and a key hub for Western military aid to Kyiv.

In 2020, Poland and the US signed the Enhanced Defense Cooperation Agreement, expanding military cooperation and helping to formalise a longer-term American military presence in the country.

How has Poland responded?

Nawrocki welcomed Trump’s announcement, calling the Polish-American alliance “a vital pillar of security for every Polish home and for all of Europe”.

“Good alliances are those based on cooperation, mutual respect, and a commitment to our shared security,” he wrote on social media.

Polish Foreign Minister Radek Sikorski also welcomed the news, saying the deployment would ensure that “the presence of American troops in Poland will be maintained more or less at previous levels”.

German Foreign Minister Johann Wadephul also welcomed the move.

“It serves not only for Poland’s security, but for the security of the whole alliance and so also for us,” he told reporters. “So, this is absolutely in our interest.”

Why is Trump doing this?

The announcement appears to mark a sharp reversal from recent signals that the Trump administration was preparing to reduce the US military’s footprint in Europe.

Earlier this month, Washington announced plans to withdraw 5,000 troops from Germany after a public row between Trump and German Chancellor Friedrich Merz over the US-Israeli war on Iran. Trump later suggested the cuts could go even further.

At the same time, Trump has repeatedly accused European NATO allies of failing to spend enough on defence and of not doing enough to support US policy in the Middle East.

Analysts say the decision over Poland also reflects Trump’s increasingly transactional approach to alliances – punishing governments he sees as hostile or unhelpful while rewarding leaders and countries more closely aligned with his brand of right-wing politics.

Germany and Spain have both faced criticism from Trump administration officials in recent weeks over their positions on Iran and defence spending, while Poland’s nationalist government has cultivated close ties with Trump and the wider MAGA movement.

Before meeting NATO counterparts in Sweden, Secretary of State Marco Rubio said: “Like any alliance, it ⁠has to be good ⁠for everyone who’s involved. There has to be a clear ⁠understanding of what the expectations are.”

“The president’s views, frankly disappointment, at some of our NATO allies and their response to our operations in the Middle East – they’re well documented – that will have to be addressed,” Rubio added. “That won’t be solved or addressed today.”

Poland, by contrast, has emerged as one of NATO’s highest defence spenders, allocating about 4.5 percent of its gross domestic product (GDP) to defence. It has also remained one of Ukraine’s strongest backers and has consistently pushed for a larger US military presence on its territory.

The deployment, therefore, appears both strategic and political – reinforcing NATO’s eastern flank while rewarding one of Trump’s closest allies in Europe at a time when he is openly questioning relationships with other partners on the continent.

But the confusion surrounding the announcement has also highlighted a broader uncertainty hanging over Washington’s Europe policy, with allies still trying to determine whether the administration is reducing its commitment to NATO overall, or simply reshaping it around governments Trump sees as more loyal.