The word other than 'foreign' that you're looking for is 'capitalist', but as you seem to be specifically talking about foreign capital, there's no need to be squeamish.

Foreign capital is unlikely to invest with the intention of collapsing the US economy. Investors invest to get a return. Any collapse that follows is simply from the weight of the contradictions of capitalism. If foreign capital is permitted to sharpen those contradictions, it's only because domestic (neoliberal) capital has created a system to facilitate such practices because it also benefits from it.

There are vulture capitals, of course, but the US has these aplenty and any foreign capitalists looking to do shock treatment to the US are a drop in a deep and wide ocean. Who needs foreign capital for that when the domestic state is run for exactly that purpose?