US-Japan summit puts new pressure on Korea over Hormuz mission

Japanese Prime Minister Sanae Takaichi waves to well‑wishers at Haneda Airport, Wednesday, as she departs for Washington, D.C. for a summit with U.S. President Donald Trump the following day. AFP‑Yonhap

Korea faces intensifying pressure to respond to U.S. President Donald Trump's demand for allied warships in the vital Strait of Hormuz, with analysts warning that the summit between Trump and Japanese Prime Minister Sanae Takaichi — slated for later Thursday in Washington, D.C. — could leave Seoul with little diplomatic room to keep leaving the request unanswered.

Both Korea and Japan were repeatedly mentioned as Trump stepped up pressure for warships to protect the shipping route off the cost of Iran.

However, East Asian allies, along with China and NATO members, have yet to respond or rebuff Trump’s call, while Iran has effectively shut down the Strait of Hormuz amid the U.S. and Israel's continued war campaign.

Analysts said the Hormuz question is likely to be addressed at the Trump-Takaichi talks and that Korea would feel the consequences of however Tokyo responds.

“The summit represents an unprecedented level of pressure on Korea after it remained silent and tried to buy time, given the shared traits with Japan that Trump has been addressing,” said Cho Han-bum, a senior research fellow at the state-run Korea Institute for National Unification.

Park Won-gon, a professor of international studies at Ewha Womans University, pointed out that “if Japan decides to participate and Korea stays out, Trump would naturally impose consequences on us.”

The analysts pointed to the two East Asian allies’ reliance on U.S. security for defense, as well as on global oil imports through the strait, which accounts for roughly 20 percent of the world’s oil trade.

Trump, while incorrectly citing the statistics, said Monday, that the U.S. has 45,000 troops in Japan, 4,500 in Korea and 50,000 in Germany, referring to the three countries with the highest combined U.S. troop presence globally. The actual figures differ, with about 5,000 in Japan, 28,500 in Korea and roughly 35,000 in Germany.

As for each country’s share of crude oil imports transiting the Gulf shipping route, Trump said 95 percent for Japan, 90 percent for China and 35 percent for Korea. The figures diverge from those of the Korea Energy Economics Institute, which showed 69 percent for Japan, 49 percent for China and 62 percent for Korea, as of 2024.

“But whether the figures are correct would not matter to Trump in relation to the summit with Takaichi,” Cho said. “What would matter for Trump would be the analogy between Seoul and Tokyo, reinforcing pressure on Seoul if it does not respond as Tokyo does on the occasion of the U.S.-Japan summit.”

He also noted that the analogy would heighten Trump's longstanding criticism of defense cost-sharing, having previously accused both Korea and Japan of exploiting U.S. security commitments and taking a “free ride.”

That frustration boiled over Wednesday, when Trump suggested he could walk away and leave the countries that rely on the strait to secure it themselves if they kept refusing to fight alongside U.S. forces against Iran.