Because until recently that was part of the sales pitch. The post-WW2 political order was that the US Govt was the security guarantor for the "western world," which meant countries allied with the US traded an almost unparalleled security guarantee for things like dollar hegemony and trade policies they probably wouldn't have acceded to otherwise. The Iraq war severely strained that bargain, and Trump's effectively broken it, but for the entire latter half of the 20th century, "this company is part of the American Military-Industrial Technosphere" was why you did business with them.