At the 2018 NATO summit, Trump threatened to withdraw the US from the alliance. FT:

Republican Donald Trump, who was the US president in 2018, threatened to withdraw the country from NATO. This was reported by the Financial Times (FT) newspaper, citing the sources of the participants of the summit. According to their memories, this event was "a turning point in the history of the alliance". Thus, Trump accused the allies of being dishonest with the United States and said that if all NATO countries do not increase their defense spending, the United States will leave the North Atlantic Alliance. "Until [January 1, 2019], all NATO countries must promise to increase defense spending, otherwise we will leave [the alliance] and will not protect those who do not," the publication quoted the former US president as saying. He also called on European NATO members to spend twice as much on defense as the alliance's goal of 2% of GDP, and recalled that many of Washington's allies "have for many years owed huge amounts of money to [U.S. ]".During the summit, Trump also pointed out the negative consequences of the migration policy of the German leadership. According to his estimates, the large number of immigrants in the country represents a potential threat to its security in the future, which Germany will counter with the help of the United States. On July 3, Foreign Policy magazine reported that during his presidency, Trump intended to reduce the American military presence in Germany. In early 2024, he also announced that he was ready to give Russia leeway to deal with NATO member states if they defaulted on their financial obligations to the alliance. According to the publication, over the past few months, Western countries have been taking measures to create mechanisms that can neutralize Trump's potential decisions if he comes to power. We are talking, in particular, about providing assistance to Ukraine, consolidating NATO and EU obligations, increasing the number of armed forces in Europe and increasing military spending.