Japan last month signed a $6 million contract for studies led by the Defense Department and two Joint Strike Fighter contractors that will outline options for how Japanese companies could manufacture components and play a role in assembling the conventional-take-off-and-landing F-35 aircraft that Tokyo plans to buy, according to DOD officials. Frank Kendall, the Pentagon's acting acquisition executive, and Vice Adm. David Venlet, the F-35 program office director, disclosed the Feb. 1 contract signing with Japan in testimony prepared for...