GAME CHANGER: Trump Approves South Korea’s Nuclear Submarine Ambition.

After his summit with South Korean President Lee Jae-myung on the sidelines of the 2025 APEC Summit in Gyeongju, South Korea, U.S. President Donald Trump announced that the United States has authorized South Korea to build nuclear-powered submarines (SSNs). The decision sent ripples across global strategic and non-proliferation circles.

In a social media post on October 29, Trump declared that the South Korea-U.S. alliance “is stronger than ever before and, based on that, I have given them approval to build a Nuclear Powered Submarine.”

In a separate post, he added, “South Korea will be building its Nuclear Powered Submarine in the Philadelphia Shipyards, right here in the good ol’ U.S.A.”

In these posts, Trump reframed one of the most sensitive defense-technology barriers in U.S. alliance policy – and did so in his typically public, unscripted manner.

That’s a big part of what makes these big changes so much fun.