Washington’s approval for Seoul’s SSNs was more signal than substance – but it reveals the shifting balance of trust and dependence shaping the alliance.

The Republic of Korea Navy submarine Na Dae-Yong (SS-069) prepares to moor alongside the Emory S. Land-class submarine tender USS Frank Cable (AS 40) at the ROK Navy base in Jeju-Do, Oct. 11, 2024.

U.S. President Donald Trump’s late October visit to South Korea, framed as a historic breakthrough, came at a moment when both allies are redefining the balance between trust and autonomy. Washington’s long-awaited decision allowing Seoul to develop nuclear-powered submarines made headlines as a sign of growing confidence. However, beneath the surface, the story was more complex.

No contracts have been signed, no fuel-cycle waivers have been granted, and Seoul’s industry ministry stated that it had not been briefed on the details. The “approval” was a political gesture – a signal of unity presented as strategic progress, rather than the beginning of an actual program. It reflected Trump’s tendency to connect commercial and security interests, transforming defense policy into a stage where both leaders could claim success at home.

For South Korea, the moment was significant but also brought uncertainty about the future. Nuclear propulsion promises to expand the Republic of Korea Navy’s reach from the Yellow Sea to the broader Indo-Pacific, enabling patrols near Taiwan and the Luzon Strait alongside