The U.S. Air Force is planning to put its aging fleet of B-52 nuclear-armed bombers back on 24-hour ready alert for the first time in 25 years, according to the Defense One newsletter.

“I look at it more as not planning for any specific event but more for the reality of the global situation we find ourselves in,” Air Force Chief of Staff Gen. David Goldfein told the publication.

The move comes amid an escalating war of words between President Donald Trump and North Korean leader Kim Jong Un, and deteriorating U.S. relations with Iran after the president decertified the landmark 2015 nuclear deal with Tehran last week.

The Boeing Stratofortress fleet sat on purpose-built runways from the 1950s to the end of the Cold War, ready to fly at the first sign of Soviet hostility. The B-52s were subsequently used in the first Gulf War, and remain in action as a heavy bomber for conventional weapons, deployed to conflict zones around the world.