The Pentagon's top brass are homing in on about 10 issues identified this summer as crucial matters for the next president and his Defense Department transition team to address as they take the reins of the U.S. military bureaucracy early next year, according to Pentagon officials. Nearly all of the top issues are classified secret, and most deal with geopolitical challenges, these officials say. They are part of a wider package of 90 briefings detailing issues of lesser import that...