BEIJING, April 22 -- While outcries from Japan's neighbors barely died away over visits to a controversial war shrine by two cabinet ministers, 146 Japanese lawmakers turned up en masse in the Tokyo shrine on Tuesday, a new act of provocation that would further worsen the island's already tense relations with its neighbors.

In addition, the trip of nearly a fifth of Japanese lawmakers to the Yasukuni Shrine puts U.S. President Barack Obama in an awkward situation as it happened trickily on the eve of his three-day state visit to Japan.

Any visit to the shrine by politicians, which honors 14 Class-A war criminals in WWII along with Japan's war dead, angers Japan's neighbors, which suffered untold atrocities committed by imperial Japan.

The United States itself also fell victim to Japan's aggression in WWII.

After Japanese Prime Minister Shinzo Abe's shrine visit last December, Washington expressed "disappointment" and called on Tokyo to engage in constructive dialogue with its neighbors over history and territorial disputes.

Obama may find his "Pivot to Asia" strategy hijacked by Japan's right-wing politicians, who care more about domestic politics than Japan's overall national interests in maintaining good relations with its Asian neighbors and the United States.

Although having decided not to pay tribute to the shrine in person this time, Abe dedicated a "masakaki" tree on Monday, in an obvious attempt to play both ways -- avoid further embarrassing Obama diplomatically and at the same time appease right-leaning forces domestically.

Given the collective spring worship at the Yasukuni Shrine a day before his arrival, Obama may find himself on a tightrope.

Silence over the shrine visit will deprive him of high moral ground given the fact that he will later on travel to South Korea and the Philippines, two countries that suffered greatly from Japanese aggression in WWII.

Siding with Japan, which behaves like a spoilt child of the United States, will also anger China and runs counter to Obama's commitment to forging a "new type of major-country relations" with Beijing.

The U.S. president should keep a vigilant eye on its Asian ally that has for long tried to whitewash its history of aggression and boost its self-defense capacities, which poses a threat not only to its Asian neighbors but to peace of the world at large. A militarist Japan is not in the interests of the United States, either.

A Japan that is reckless in dealing with other regional powers, including China and South Korea, will eventually turn out to be negative in Washington's "rebalance to Asia" policy.