The main problem with the US at the moment is the division in our society over socio-cultural and political issues. Some of this has been stoked from abroad, but the wedge has been there for a while. Once there's a clear winner on those issues, the US will likely pull itself together. It seems to happen in the US in about 50-60 year intervals and we usually pull our shit together afterward. There is a chance we won't and that won't be pretty, of course.
The real problem is the danger the collapsing USA poses to the rest of the world. Ever since 9/11 America has been stumbling around like a drunk looking for a fight at closing time, destroying one country after another with absolutely no compunction. Its losing its economic hegemony while retaining its military dominance, which is an extremely dangerous situation.