America has on occasion, betrayed its allies and broken treaties. The difference is, up until present, these actions were hidden.
It has come to light, of course, that treaties made with the native population were often tricks, and the term; “white man speaks with forked tongue” has had some currency.
Depending on America has never been wise.
Certain nations, due to their financial use, can expect special treatment, other nations and groups will be used, then discarded when the ‘cost’ of support is more than the ‘cost’ of abandonment.
That Trump pulled out of treaties, either oblivious or uncaring of the result. was standard. That he will abandon allies; i.e. the Kurds as if flushing a toilet is common.
Simply put, Trump sees no need to maintain the fiction of America. He sees no need to pretend that ‘All Men are Created Equal’ or that there are ‘Inalienable Rights’.
Trump cared about Trump; and now, destroying American Democracy, bringing an election into derision, is a shrug.