Some foreign policy experts took issue with Trump’s assertions about contributions to NATO. Ivo Daalder, a former U.S. ambassador to NATO, took to Twitter to argue that Trump didn’t seem to understand how the alliance works.

“US does provide large military commitment to NATO. But this is not a favor to Europe. It is vital for our own security,” Daalder tweeted. “All NATO countries, including Germany, have committed to spend 2% of GDP on defense by 2024.”

Daalder said America’s contribution to NATO is not to help pay for Germany’s defense or that of other European allies. “It is part of our treaty commitment,” he noted.

Trump doesn’t understand how NATO works, former ambassador says

Yup.