In a phone conversation with Philippine President Rodrigo Duterte, U.S. President Donald Trump revealed that the U.S. Navy has sent two nuclear-powered submarines to the waters off the Korean Peninsula.
Discussing North Korea’s nuclear weapons program, the U.S. president told his Philippine counterpart that the United States has a lot of “fire power” on and off the peninsula. “We have two submarines — the best in the world — we have two nuclear submarines — not that we want to use them at all,” Trump said, according to the transcript, which was first made public by The Intercept on May 23. “I’ve never seen anything like they are, but we don’t have to use this, but he could be crazy so we will see what happens.”
Trump was likely referring to an Ohio-class guided missile submarine (SSGN), the USS Michigan, which made an official port call in Busan, South Korea on April 25, and the Los-Angeles-class attack submarine (SSN) USS Cheyenne, which visited Sasebo, Japan on May 2 as part of its regional deployment. While the deployment of USS Michigan was publicly known prior to the phone call between the two presidents, it appears that the whereabouts of the USS Cheyenne were only made public a few days after the Duterte-Trump conversation.
Considering that the U.S. Navy does not publicly announce the movement of its submarines, it is impossible to know whether Trump was referring to the two boats mentioned above or other subs deployed in the vicinity of the Korean Peninsula. U.S. Navy submarines usually operate alone, but sometimes have a direct support role in a carrier strike group (CSG). While, the U.S. Navy usually publicly announces the deployment of a CSG listing the aircraft carrier and accompanying surface warships, it does not disclose the presence or designation of its undersea escort.
By revealing to the Philippine president the presence of U.S. submarines off the Korean Peninsula, Trump did not disclose classified information. Nevertheless, it is a highly unorthodox move to alert a foreign leader to the deployment of submarines and it is bound to upset the U.S. fleet commander. While Trump did not specify the exact location of the submarines, the mere mentioning of the exact number of subs in the area would theoretically have made it easier for North Korea to track the U.S. boats. According to most analysts, however, the Korean People’s Navy does not possess an advanced anti-submarine warfare capability.
The U.S. Navy on average is deploying up to ten Los-Angeles, Seawolf, or Virginia-class attack submarines across the globe every day.