Alva Review-Courier -

CHEORWON, South Korea (AP) — To the steady rat-tat-tat of machine guns and exploding bursts of smoke, amphibious tanks slice across a lake not far from the big green mountains that stand along the world's most heavily armed border.

Dozens of South Korean and U.S. combat engineers build a pontoon bridge to ferry tanks and armored vehicles across the water, all within easy range of North Korean artillery.

For seven decades, the allies have staged annual drills like this recent one to deter aggression from North Korea, whose 1950 surprise invasion of South Korea started a war that has technically...