Republican presidential front-runner Donald Trump stunned U.S. military officials and the defense policy establishment with his suggestion this month that the U.S. should stop trying to prevent its allies South Korea and Japan from obtaining nuclear weapons.
The idea contradicts long-standing U.S. policy, but as North Korea continues to defy international efforts to curb its nuclear ambitions and China continues to turn a blind eye to Pyongyang’s efforts, not everyone is dismissing Mr. Trump’s idea out of hand.
Mr. Trump, whose campaign has shown a readiness to challenge foreign policy positions long championed by both Democrats and Republicans, roiled U.S. and international leaders after repeatedly suggesting that Japan and South Korea should acquire nuclear weapons and saying at one point that it was “just a matter of time.”
“You have so many countries already — China, Pakistan, you have so many countries, Russia — you have so many countries right now that have them,” Mr. Trump said at a Milwaukee town hall last month. “Now, wouldn’t you rather, in a certain sense, have Japan have nuclear weapons when North Korea has nuclear weapons?”
Mr. Trump again raised the issue in a New York Times interview this month. He said a nuclear-armed Japan and South Korea could not be dismissed in the face of North Korea’s growing threat in the region, with China incapable or unwilling to rein in its ally. He also said the shift would ease the financial and strategic burdens for the U.S. military.
“The last person to use nuclear would be Donald Trump,” he told the newspaper. “That’s the way I feel. I think it is a horrible thing — the thought of it is horrible. But I don’t want to take anything off the table.”
His comments drew swift rebuke from the White House, Tokyo and Seoul, where officials said any move to add members to the world’s nuclear club would destabilize the already tenuous security situation in the Asia-Pacific region.
But with North Korea and China reportedly conducting nuclear weapons testing this month, U.S. allies in the region may begin feeling the heat to develop their own. It wouldn’t be a technological stretch for either economy.
Tokyo has “all the required technology at an advanced stage” to have a viable nuclear weapon developed and fielded within a year, said Michael J. Green, a top adviser on Asian affairs in the George W. Bush administration who is now with the Center for Strategic and International Studies.
Seoul would likely take longer to get a nuclear weapons program off the ground because South Korea’s fissile technology is behind that of Japan, Mr. Green said. But there is no question, if prompted, that both countries could join the global fraternity of nuclear powers.
“That is a fact. They could do it,” Mr. Green said.
Whether either country wants nuclear weapons is another question, one haunted by history and colored by the shifting power dynamics in East Asia.
South Korean split
South Korean President Park Geun-hye quickly rejected Mr. Trump’s suggestion, telling Bloomberg News ahead of President Obama’s nuclear security summit this month that she strongly favored barring all nuclear weapons — North and South — from the Korean Peninsula.
The South Korean government “maintains an unwavering stance in support of denuclearization,” she said.
But in a widely noted editorial, one of the country’s most respected conservative newspapers said the issue isn’t so clear-cut.
“Seoul can no longer sit idly by as the [nuclear] talks lead to no results and Washington and Beijing are busy blaming each other for their diplomatic failures,” the Chosun Ilbo wrote in its editorial, published shortly after another North Korean nuclear test at the beginning of the year.
In February, Won Yoo-chul, a floor leader in parliament for Ms. Park’s ruling Saenuri Party, said the South should develop “peaceful” nuclear weapons to deter North Korea’s “fearful and self-destructive” ones.
Although the Defense Ministry rejected his comments, Mr. Won said Seoul could not rely on Washington forever to protect it from its implacable next-door neighbor.
“We can’t borrow umbrellas from next door every time it rains. We should wear a raincoat of our own,” Mr. Won said.
Polls show that Mr. Trump’s idea is popular with ordinary South Koreans. National surveys in 2013 and in February this year found a clear majority in favor of South Korean development of its own nuclear arsenal.
Perceived American missteps in the Middle East and Eastern Europe, combined with North Korean and Chinese aggression in the Pacific, have only inflamed those sentiments.
“Judging by Washington’s inaction in the military crises in the Ukraine and Syria, it would probably respond only after Seoul has been turned into a pile of smoldering ashes,” the Chosun Ilbo editorial warned.
Despite Mr. Trump’s success on the campaign trail, the conventional wisdom among defense analysts remains that any effort to secure nuclear weapons by either Japan or South Korea would upend the entire security apparatus in the region.
“A move by either country to nuclear weapons would undoubtedly be used as a justification by North Korea to expand its own nuclear arsenal and improve its ballistic missiles,” said Kelsey Davenport, director of nonproliferation policy at the Washington-based Arms Control Association.
While noting that it would be “highly improbable” for Tokyo or Seoul to pursue armed nuclear capabilities, such a move “could spark an arms race in the region if the two countries tried to achieve parity with each other or China.”
A nuclear-armed Japan or South Korea “would risk global security with almost no upside,” said Patrick Cronin, senior director of the Asia-Pacific Security Program at the Washington-based Center for a New American Security.
By moving toward nuclear weapons development, South Korea, Japan or any other U.S. ally in the region would violate numerous international nonproliferation pacts and undermine the so-called U.S. nuclear umbrella.
“A renewed effort to build nuclear weapons on the part of either Tokyo or Seoul or both would signal that the U.S. alliance system is broken,” moving China to either offer its own nuclear umbrella to other U.S. allies in Asia or sabotage efforts by those allies to develop their own nuclear arsenals, Mr. Cronin said.
“All of these countries and others — including Russia — would have to prepare for split-second decisions,” he said. “In the age of cyberwarfare, early-warning information may be increasingly unreliable, heightening the chances of accidental nuclear war.”