is the accusation here that the US is not loyal? or that they have breached a treaty, contract or even an explicit promise? if so which precisely?
many easy searches will give you lists, this is just one
When Trump did not get the Nobel Peace Prize, his response was "I no longer need to think purely of peace" in relation to Greenland iirc
How are other countries to interpret this?
Welcome to living among humans, where choices are made.
Every country made their choice, willingly or not, then lived by it for several generations. Now we have a generation of nationalists, we'll see how that ends up down the road for better or worse.