WASHINGTON — Across the military, officers and troops are quietly preparing for a war they hope will not come.

At Fort Bragg in North Carolina last month, a mix of 48 Apache gunships and Chinook cargo helicopters took off in an exercise that practiced moving troops and equipment under live artillery fire to assault targets. Two days later, in the skies above Nevada, 119 soldiers from the Army’s 82nd Airborne Division parachuted out of C-17 military cargo planes under cover of darkness in an exercise that simulated a foreign invasion.

Next month, at Army posts across the United States, more than 1,000 reserve soldiers will practice how to set up so-called mobilization centers that move military forces overseas in a hurry. And beginning next month with the Winter Olympics in the South Korean town of Pyeongchang, the Pentagon plans to send more Special Operations troops to the Korean Peninsula, an initial step toward what some officials said ultimately could be the formation of a Korea-based task force similar to the types that are fighting in Iraq and Syria. Others said the plan was strictly related to counterterrorism efforts.

In the world of the American military, where contingency planning is a mantra drummed into the psyche of every officer, the moves are ostensibly part of standard Defense Department training and troop rotations. But the scope and timing of the exercises suggest a renewed focus on getting the country’s military prepared for what could be on the horizon with North Korea.