Not just a "particular business-critical application" but a "non-American business-critical application", you seem to have lost the thread of the conversation. So non-American corporations that produce software and hardware solutions will have every incentive to completely separate themselves from any security corrupted American components. From a competitive standpoint this gives them something even more valuable a public argument to force purchasing changes in governments around the world away from American delivered security corrupted solutions, something they will be sure to attempt to leverage to the maximum extent possible.
American corporate response not much of a leg to stand, American government response, hmm, pretend it's not happening 'er' free trade agreements (although I am pretty sure that incorporating elements in US products to purposefully corrupt the security of other countries networks would be covered). For many corporations the NSA has provided a golden business opportunity delivered upon a silver platter, the ability to eliminate US corporations as competitors for quite some time, something they would be seriously inept to miss.