In 1966 France kicked the US military out. They did it because Charles De Gaulle was the president at that time, and as a decorated military General remembered quite clearly what it was like to live under Nazi occupation and didn't want France to live under America's influence in NATO. In 2009, France rejoined NATO but has never invited the US back so there are still no US bases on French soil. So I can see in the not so distant future that some significant countries like the UK, Germany and Italy may decide they don't want nearly 100,000 US military members on their sovereign soil. All US military bases in Europe are there solely on the good graces of the host countries. Depending on the exigencies of what could transpire quickly with Trump and his threats the drawdown of US troops and equipment could echo what happened in Afghanistan in 2021.
One thing that the US and many Americans have never experienced in modern history is occupation and the destruction of their country during active wars. So far, the US has escaped that. Even the most famous example of overt military aggression toward the US was on Pearl Harbour in 1941 which wasn't even a state back then. They were annexed in 1898 when the US overthrew the monarchy. They took it by force not negotiation. Which sounds very similar to what Trump wants to do with Greenland.