Strategic bombers, submarines have recently operated off Korean coast.
President refused to rule out eventual military action against North Korea.
The 12-day, five-country trip, the longest Far East itinerary for a president in a generation, comes at a precarious moment for Trump.
27-year-old confessed to cutting them up and hiding them.
Dow Jones industrial average fell 85.45.
Fears of remilitarization are largely exaggerated