By Richard Halloran

Several prominent U.S. conservatives recently have suggested that the Bush administration should encourage Japan to acquire nuclear weapons in an attempt to press China into dissuading North Korea from its nuclear ambitions.

Playing this Japanese nuclear card is a bad idea for plenty of reasons and, luckily, not a proposal that is likely to go very far.

The latest flurry started with the syndicated columnist Charles Krauthammer, who wrote in the Washington Post (and Advertiser, Jan. 3): "We should go to the Chinese and tell them plainly that if they do not join us in squeezing North Korea and thus stopping its march to go nuclear, we will endorse any Japanese attempt to create a nuclear deterrent."

That was followed by Sen. John McCain of Arizona, the erstwhile candidate for the Republican presidential nomination, who told a television interviewer: "One of the options that we have is, of course, to remove our objections to Japan developing nuclear weapons, since they are now directly threatened by North Korea. I'm sure the Chinese would not like to see that happen."

Then Richard V. Allen, President Reagan's first national security adviser, wrote in the New York Times that China had shown no sign of urging North Korea to desist. "We have our own cards to play," Allen said, "not least in guiding Japan to a sensible policy of considering arming itself with nuclear weapons."

The first reason for shunning this nuclear card is that few in Japan would support it. The "nuclear allergy" that is the consequence of the atomic bombings of Hiroshima and Nagasaki in 1945 is still strong. Poll after poll confirms this. Any political leader who breathes in the direction of nukes swiftly finds himself in the middle of a firestorm.

Indeed, the proposals emanating from Washington have attracted little interest in Japan except among a handful of right-wingers who would like to see the issue debated. For now, this is the dog that didn't bark.

Secondly, playing the nuclear Japan card is likely to go for naught because the Chinese just don't have that much influence in Pyongyang. More than one senior Chinese official has privately lamented to American officials that they cannot control the feisty North Koreans.

A third reason: President Bush has given priority to preventing the proliferation of nuclear weapons. To encourage Japan to go nuclear while preparing for war against Iraq and possibly North Korea to prevent those nations from building nuclear arsenals would be a mockery.

Some months ago, Peter Ennis, of the Oriental Economist Report, asserted: "There is absolutely no evidence — none whatsoever — that the Liberal Democratic Party, the Japan Defense Agency or the military branches are actively studying the possibility of Japan developing nuclear weapons. The LDP has no study group; the military has no task forces. No one is seriously looking at the issue."

Essentially, nuclear arms make no political, diplomatic, economic or, especially, military sense for Japan, even though Tokyo has the technology to develop them. As a Japanese strategic thinker said long ago, "Japan is N minus six months" — meaning that Tokyo could detonate a nuclear device within six months of a decision to do so.

The shock waves of a Japanese acquisition of nuclear arms would ripple out to the rest of Asia and would be so strong that Japanese efforts to exert diplomatic influence would be set back a half century. The reactions in Beijing, Seoul and many other capitals would be unpredictable in their consequences.

Japan has no military rationale for a nuclear force. Unlike Russia, China and the United States, Japan has no wide-open spaces into which to sink missile silos away from cities. Japan would become what military planners call a "target-rich environment." Like France, Japan could put nuclear missiles into submarines, but that would be costly. The cost of France's present program — four submarines, their missiles and supporting shipyards — has been estimated at $12.8 billion.

A caution that has been expressed in this space before: The Japanese will not feel the need for nuclear weapons so long as they are confident that the U.S. nuclear umbrella is credible, that they can count on us to deter and, if necessary, to repel aggression. Take that away and all bets are off.

The key to Japan's nuclear future is therefore held in Washington, not Tokyo. On this point, at least, Krauthammer, McCain and Allen have something going for them.

Richard Halloran formerly was a New York Times correspondent in Asia and Washington. Reach him at oranhall@hawaii.rr.com.