The United States has told the European Nato allies that it will hand over responsibility for conventional defence capabilities by 2027 and no longer act as the automatic security guarantor, Reuters reports on December 6.

The report comes one day after the White House released its latest National Security Strategy (NSS) that significantly downgrades the US relationship with Europe from the “special relations” it has enjoyed since the end of the Cold War, to merely an important commercial partner now. The new foreign policy concept was also scathing in its criticism of Europe’s political and economic problems and has caused consternation in Brussels.

It is a bald restatement of US President Donald Trump’s “America First” policy, an updated commercialized version of the Monroe Doctrine, and a confirmation that the US intends to impose its “unipolar” world view that puts it on a collision course with Russia and China.

Part of Trump’s “commercial diplomacy” stance abandons the traditional values-based outlook that Washington has shared with Brussels, and cuts the EU loose to look after itself. European allies will have to assume control of the bulk of Nato’s capabilities, many of which remain underdeveloped in Europe, which has for decades sheltered under a comprehensive US security umbrella and left its own capabilities under funded. That umbrella will now be snapped shut.

This includes surveillance, intelligence and missile systems by 2027, in a move that would represent a dramatic shift in the transatlantic military balance, Reuters reports, citing five sources familiar with the discussions.

Pentagon officials delivered the message this week during a closed-door meeting in Washington with several European delegations. It reflects growing US impatience over what Washington views as slow progress by European states in responding to Russia’s full-scale invasion of Ukraine. It is also part of Trump’s demand for Nato allies to increase their defence spending to 5% of GDP by 2032 that was agreed at the Nato summit in the Hague earlier this year. Previously, the recommendation, agreed at the Welsh summit in 2014 was 2% of GDP, but few members reached that benchmark.

“If Europe does not meet the 2027 deadline, the US may stop participating in some Nato defence coordination mechanisms,” the sources said, warning that discussions on the topic have already triggered concern among officials on Capitol Hill. Separately, the Pentagon said 2027 was a “hard deadline” and would not be extended.

Europe is already scrambling to prepare itself in anticipation of the US departure. The US has threatened to downsize its military presence in Europe. Europe has launched plans to upgrade its infrastructure across the Continent that will cost billions of euros, to make roads and bridges military-ready, but currently unsuitable to move large armies and materiel to battle zones in the north and east from the south and west. Currently the command of military logistics in Europe is entirely under US control.

In parallel, European Commission President Ursula von der Leyen launched the ReArm programme in a speech (video) on March 4 that calls for €800bn of investment into modernising Europe’s armies over the next four years. The EU has already implanted €150bn of SAFE (Security Action for Europe) military loans for the upgrade which has already been full disbursed.

Military spending has already increased dramatically in the last year but only Poland is anywhere close to reaching 5% of GDP but should cross that line in the next year. Poland has committed itself to creating the largest conventional army in Europe. Many other countries in the EU are now at or over 2% of GDP, according to data from the Stockholm International Peace Research Institute (SIPRI). In 2023, total European NATO members’ defence spending reached approximately $380bn, up from $345bn in 2022 — a 10% increase year-on-year. In particular, Germany created a special €100bn defence fund in 2022 and is on track to meet the 2% GDP threshold in 2024 for the first time in decades. 23 out of 31 Nato members are expected to meet or exceed the 2% target — up from just 6 in 2021. But it will take years to get to the 5% benchmark, if ever, say analysts.

While Nato has long operated on the principle of shared defence, the US remains its single largest contributor in both nuclear and conventional capabilities. The current proposal would accelerate efforts to reduce American exposure, particularly in areas like ISR (intelligence, surveillance, reconnaissance) where US capabilities are often irreplaceable.

“There is no clarity on how the US would measure Nato's progress,” one source told Reuters, adding that it was unclear whether the 2027 deadline reflected an official position from the Trump administration or only the views of certain Pentagon officials. Secretary of War Pete Hegseth, who oversees the Pentagon, is a hawk on Europe and previously cut Ukraine off from weapons supplies in July, warning that the US had run down its stockpiles to below what was required for the US own security plans.

The response from European capitals has been muted. Several officials said the 2027 timeline was “not realistic,” even if defence spending targets were met. Due to Europe’s failure to sign defence sector procurement contracts since the war in Ukraine started, Europe faces deep backlogs in defence production, and key US-made systems such as air defence platforms or ISR technologies may take years to deliver, even if ordered now. For example, the US only produces some 12-16 sought after Patriot systems a year that have proven highly effective in both the Ukraine war and in the clash between Israel and Iran earlier this year. But maker Raytheon says it has a backlog of at least 30 orders that will take at least five years to clear. The backlog for the PAC-3 interceptor ammo the system uses is even bigger, with orders running into the tens of thousands, especially as countries replenish stockpiles donated to Ukraine.

A Nato spokesperson acknowledged that “allies have recognised the need to invest more in defence and shift the burden on conventional defence from the US to Europe,” but declined to comment on the proposed 2027 deadline.

The European Union has independently set a goal of ensuring the continent can defend itself by 2030, including strengthening air defences, drones, cyber warfare and munitions production — though officials and analysts concede even that target is ambitious, reports Reuters.

The closing of the US security umbrella comes as Trump has indicated that the US is withdrawing from its role as global policeman as part of his new economic paradigm and transactional approach to international relations – an approach spelled out in black and white in the new NSS. On the 2024 campaign trail, Trump famously said he would “encourage” Russia to attack Nato members that are not meeting spending commitments. But at the Nato leaders’ summit in June, he praised European allies for backing a US proposal to raise the Nato spending target to 5% of GDP. Nevertheless, US support is now being withdrawn. For Trump the arms deals linked to the 5% of GDP spending boost appears to have been the goal, not bolstering European security.

The transactional nature to security is also apparent in the policies towards ending the war in Ukraine. Trump has been consistently soft on Russia, a military aggressor that is threatening all of Europe, as he has made it clear he is primarily interested in doing business with Russia. He has shifted from a hard rhetoric but no sanctions, line on Russia to sponsoring the 28-point peace plan (28PPP) that is packed full of business deals, but offers Ukraine little in the way of post-war security. As bne IntelliNews reported, at the recent Moscow meeting on December 3 Europe’s security concerns were completely ignored by the US delegation.

With US political uncertainty rising ahead of the 2028 election, Nato’s European members are now under pressure to deliver not only on spending promises, but also on operational readiness, in case Washington’s security guarantees become less reliable.