Donald Trump damaged NATO unity by putting American interests first during his time in the White House, US President Joe Biden has said.

Biden, who last month dropped out of the 2024 presidential race in favor of Vice President Kamala Harris, lashed out at the Republican nominee during a speech at the Democratic National Convention in Chicago on Monday. One of his lines of attack was over the damage he claimed Trump had done to NATO during his term as president.

“When Trump left office, Europe in NATO was in tatters – not a joke. [The] America First doctrine changed our whole image in the world,” Biden said, referring to the key policy of Trump’s 2016-2020 presidency.

Trump has accused European members of the US-led bloc of being freeloaders, who fail to spend enough on their military and instead rely on American protection for national security. The Republican has also claimed that while in office, he threatened to renege on the US commitment to defend “delinquent” NATO nations.

Biden told Democratic delegates that he had spent some 190 hours talking to heads of states in Europe, mending relations after Trump. “We united Europe like it had been united for years, adding Finland and Sweden to NATO,” he stated. The two previously neutral Nordic nations joined the bloc amid the Ukraine conflict.

The president claimed that the late Henry Kissinger had called him days before his death in November 2023 to praise him. According to Biden, Kissinger said Europe had been looking at Russia “with dread” since Napoleonic times “until now.”

Napoleon invaded Russia in 1812 but later retreated with his army in tatters. Trump has cited the example, saying “they’ve defeated Hitler, they’ve defeated Napoleon,” to explain why he considers Moscow a formidable military adversary that should not be tested on the battlefield.