A leaked internal Pentagon memo obtained by Reuters has exposed unprecedented proposals from the United States to impose punitive measures on NATO allies that the Trump administration accuses of failing to back the US and Israel during their late February military campaign against Iran. The controversial plans include the radical step of suspending Spain’s membership in the 77-year-old transatlantic alliance and reopening a formal review of the United Kingdom’s long-recognized sovereignty over the Falkland Islands.
The disclosure comes amid a sustained wave of public criticism of NATO from President Donald Trump, who has spent months lashing out at member states for their perceived lack of support following the Iran conflict, which led to Iran imposing restrictions on commercial shipping through the strategically critical Strait of Hormuz. Trump has repeatedly questioned the alliance’s relevance, even labeling it a “paper tiger” and openly floating the possibility of a full US withdrawal from the bloc. In a post on his Truth Social platform following a recent meeting with new NATO Secretary General Mark Rutte, the president doubled down on his stance, writing bluntly: “NATO WASN’T THERE WHEN WE NEEDED THEM, AND THEY WON’T BE THERE IF WE NEED THEM AGAIN.” He has also consistently accused fellow member nations of free-riding on the massive US military investment that underpins collective transatlantic security.
NATO officials pushed back immediately on the suspension proposal, telling the BBC that the alliance’s founding treaty contains no legal mechanism to suspend or expel a member state. Downing Street also rejected the suggestion of reviewing Falkland Islands sovereignty, reaffirming that the UK’s claim to the territory remains unambiguous and fully rooted in the self-determination of the islands’ population.
Founded in 1949 in Washington D.C. by 12 original signatory nations, NATO was initially created to counter Soviet expansion in Europe and foster political integration across the continent to prevent the resurgence of nationalist militarism. Today, the alliance counts 32 member states spanning North America and Europe, with the most recent expansions bringing Finland into the bloc in 2023 and Sweden in 2024, both abandoning decades of neutrality after Russia’s 2022 full-scale invasion of Ukraine. Ukraine, Bosnia and Herzegovina, and Georgia hold official candidate status and have formally requested membership.
At the core of NATO’s collective defense framework is Article 5, which states that an armed attack against any single member is considered an attack against all, requiring members to take whatever action they deem necessary to restore security. To date, Article 5 has only been invoked once, in response to the 9/11 terrorist attacks against the United States in 2001. A separate provision, Article 4, allows members to bring pressing security concerns to the alliance’s main decision-making body, the North Atlantic Council, and has been used seven times since the alliance’s founding.
In 2025, NATO leaders agreed to a landmark new defense spending target requiring all members to commit 5% of their national GDP to defense-related expenditure by 2035. Of that total, 3.5% must go toward core defense capabilities, with up to an additional 1.5% allocated to broader security infrastructure. Prior to this agreement, members operated under a non-binding 2% target, which all alliance nations finally met for the first time in 2025. The United States remains by far the alliance’s largest defense spender, contributing roughly $980 billion in 2025 – accounting for 60% of total NATO defense spending across all members. Poland, Lithuania, and Latvia, all frontline states facing direct Russian pressure, each spent over 3.5% of GDP on defense in 2025, while the UK reported 2.3% of GDP spent on defense that year, with a government target to reach 3% by the end of its next parliamentary term.
Ukraine’s path to NATO membership remains one of the alliance’s most contentious issues. Russia has vehemently opposed Ukraine’s accession, viewing the expansion of alliance infrastructure to its border as an existential security threat. After the 2022 invasion, Ukrainian President Volodymyr Zelensky pushed to accelerate the accession process, but former NATO Secretary General Jens Stoltenberg confirmed membership would only move forward after the conclusion of active hostilities. Most recently, in August 2025, President Trump stated that Ukraine would not be permitted to join NATO as part of any proposed peace deal with Russia, placing a major new cloud over Kyiv’s long-term membership aspirations. While NATO has labeled Russia’s invasion of Ukraine the most direct threat to transatlantic security in decades, the alliance has declined to deploy direct military support or impose a no-fly zone over Ukraine to avoid a direct armed conflict with nuclear-armed Russia. Individual member states, however, have provided billions of dollars in military and humanitarian aid to Kyiv since the invasion began.