“”I DOUBT NATO WOULD BE THERE FOR US IF WE REALLY NEEDED THEM,” Trump blasted on Truth Social, while insisting the U.S. would still defend alliance members. “We will always be there for NATO, even if they won’t be there for us.”
Under Article 5 of the North Atlantic Treaty, NATO’s collective defense clause, an attack on one member of the alliance is considered an attack on all. The provision has been formally invoked only once — in response to al-Qaida’s 9/11 terror attack against the U.S.”
https://www.politico.eu/article/us-donald-trump-nato-allies-greenland-crisis-deepens