Imagine that North Korea launched a missile at Japan. Tokyo could — and would certainly try to — shoot it down. But if the missile were flying overhead toward Hawaii or the continental United States, Japan would have to sit idly by.

Japan's military is kept on a very short leash under a war-renouncing constitution written by U.S. officials whose main concern was keeping Japan from rearming soon after World War II. But if Japan's soon-to-be prime minister Shinzo Abe has his way, the status quo may be in for some change.

Abe, set to take office for a second time after leading his conservative party to victory in elections last Sunday, has vowed a fundamental review of Japan's taboo-ridden postwar security policies and proposed ideas that range from changing the name of the military — now called the Japan Self-Defense Forces — to revising the constitution itself.

Most of all, he wants to open the door to what the Japanese call "collective defense," which would allow Japan's troops to fight alongside their allies — especially the U.S. troops who are obliged to defend Japan — if either comes under direct attack. The United States has about 50,000 troops in Japan, including its largest air base in Asia.

Right now, if Japan's current standoff with China over a group of disputed islands got physical, and U.S. Navy ships coming to Japan's assistance took enemy fire, Japan wouldn't be able to help them.

"With the U.S. defense budget facing big cuts, a collapse of the military balance of power in Asia could create instability," Abe said in the run-up to the election, promising to address the collective defense issue quickly. "We must foster an alliance with the United States that can hold up under these circumstances."

While welcome in Washington, which is looking to keep its own costs down while beefing up its Pacific alliances to counterbalance the rise of China, Abe's ideas are raising eyebrows in a region that vividly remembers Japan's brutal rampage across Asia 70 years ago.

"The issue of whether Japan can face up to and reflect upon its history of aggression is what every close neighbor in Asia and the global community at large are highly concerned about," Chinese Foreign Ministry spokeswoman Hua Chunying told a news conference in Beijing this week. She said any move to bolster the military "deserves full vigilance among the Asian countries and the global community."

Even so, many Japanese strategists believe the changes are long overdue.

Japan has one of the most sophisticated military forces in the world, with a quarter million troops, a well-equipped navy and an air force that will acquire dozens of F-35 Joint Strike Fighters over the next several years, in addition to its already formidable fleet of F-15s. Japan's annual defense budget is the world's sixth largest.

"We should stand tall in the international community," said Narushige Michishita, who has advised the government on defense issues and is the director of the security and international program at Tokyo's National Graduate Institute for Policy Studies.

"These are good, well-trained conventional forces," he said. "We are second to none in Asia. So the idea is why don't we start using this. We don't have to start going to war. We can use it more effectively as a deterrent. If we get rid of legal, political and psychological restraints, we can do much more. We should start playing a larger and more responsible in international security affairs."

Outside of very constrained participation in U.N.-sanctioned peacekeeping operations and other low-intensity missions, Japan's military is tightly restricted to national defense and humanitarian assistance. Although Japan did support the U.S. wars in Iraq and Afghanistan, its troops were kept well away from frontline combat.

Such restrictions, seen by conservatives as a postwar relic that has kept Japan from being a bigger player on the international stage, have long been one of Abe's pet peeves.

When he was first prime minister in 2006-2007, he was so disturbed by the kinds of crisis scenarios in which Tokyo's hands were tied that he commissioned a panel of experts to explore Japan's options. He left office before the report could be completed. His party was ousted from power two years later, and the issue was essentially dropped.

This time around, it's not clear how effectively or how soon Abe will be able to push the military issue, since stimulating the nation's economy will be his first task, and he faces strong opposition in parliament, where he has been slammed as a historical revisionist and a hawk.

But with the daily cat-and-mouse game between the Chinese and Japanese coast guards over the disputed islands not expected to end soon, polls indicate support for beefing up the military is stronger than ever.

"These are real issues, important issues," Michishita said. "And I think Abe will try to do something about it."


Associated Press researcher Zhao Liang in Beijing contributed to this report.