Republican frontrunner Donald Trump is known for his tendency to stir up controversies with unexpected and bewildering comments. This time, he has managed to shock two of America’s strongest allies in the east, Japan, and South Korea, by his proposal to withdraw the US military troops from their shores and replace them with nuclear weapons.

About 54,000 US troops are based in Japan and 28,000 in South Korea, the CNN reported.

“Japan is better if it protects itself against this maniac of North Korea,” Trump told the CNN on Tuesday. “We are better off frankly if South Korea is going to start protecting itself … they have to protect themselves or they have to pay us.”

Trump’s comments raised so much concern in the region that Japan’s Prime Minister Shinzo Abe responded publicly saying, “whoever will become the next president of the United States, the Japan-U.S. alliance is the cornerstone of Japan’s diplomacy.”

Japan remains the only country which has suffered destruction caused by a nuclear weapon. Since the end of the World War II, it has adopted a non-nuclear policy and a pacifist constitution.

Japanese Foreign Minister Fumio Kishida said that it is impossible that Japan would use nuclear weapons to arm itself.

“This is basically like, ‘Hey, maybe we should think about communism,'” the Vox quoted Jennifer Lind, a professor at Dartmouth who studies East Asia, as saying. “With one blasé comment, this entire foundation of US grand strategy is just blasted away.”

She added, “Japan, as a country, has deep-seated anti-nuclear sentiment, based on the variety of experiences they’ve had with this technology.”

However, a small section in South Korea think there could be some basis in Trump’s argument and welcomed the idea. However, the support doesn’t reflect the idea of the mainstream.

Cheong Seong-Chang, an academic from the non-profit think-tank the Sejong Institute, said, “If we have nuclear weapons, we’ll be in a much better position to deal with North Korea.”