The House is poised to pass legislation that gradually ramps up "Buy American" requirements on the Defense Department's largest programs of record, but industry representatives and analysts say the "arbitrary" rules could trip up important weapons developments and hurt international cooperation on defense programs. At the heart of the debate is lawmakers' desire to create American manufacturing jobs and reduce U.S. reliance on foreign sources. The language, inserted via amendment into the House Armed Services Committee's fiscal year 2021 defense...