The surprise announcement by Japan earlier this week to halt plans for Aegis Ashore acquisition and deployment could potentially be reversed once "concerns and issues" about the weapon system are resolved, a senior U.S. military official said. Missile Defense Agency Director Vice Adm. Jon Hill said the Defense Department is working with Japan's defense ministry to get plans back on track for a land-based variant of the Aegis weapon system -- a $2.2 billion project that was intended to reduce...