US President Barack Obama landed in Tokyo Wednesday to launch anAsian tour dedicated to reinvigorating his policy of "rebalancing" US foreign policytowards a dynamic Asia.Obama landed aboard Air Force One to begin a state visit to Japan, which comes asregional tensions boil over maritime territorial disputes and fears that North Koreacould soon carry out a new nuclear test.The president touched down a day after nearly 150 lawmakers paid homage at acontroversial Tokyo war shrine seen by neighbouring nations as a symbol of Japan'sbrutal imperialist past, and shortly after the prime minister made a shrine offering.Days earlier, China seized a huge Japanese freighter over what a Shanghai courtsays are unpaid bills relating to Japan's 1930s occupation of vast swathes of thecountry.In the seas to the southwest, boats from China and Japan spar for ownership of asmall chain of islands. And an ever-unpredictable North Korea -- which hasdenounced the presidential tour as "reactionary and dangerous" -- appears to betrying to seize the spotlight with preparations for a fourth nuclear test. Despite the increasingly tense security situation, getting top regional US alliesJapan and South Korea -- Obama's next destination -- to talk to each other is tricky.South Korean President Park Geun-Hye and Japanese Prime Minister Shinzo Abe havemet just once since both came to power over a year ago, and only then when the USleader cajoled them into a choreographed photo opportunity.East Asia is a tumultuous region with a multitude of fractures that the US has donelittle to mend over the last half-century, said Christian Wirth, a research fellow atGriffith University in Australia."Since the establishment of the post-war regime in San Francisco in 1951 and theonset of the Korean War in 1950, (the US has been) directly and deeply involved inEast Asian politics," he told AFP."Washington’s preference for bilateralism has contributed to the lack of intra-Asiancooperation and historical reconciliation."That bilateralism begins Wednesday evening with a one-on-one dinner betweenObama and Abe, reportedly at an exclusive sushi restaurant in the basement of anageing office building in the glitzy Ginza district of Tokyo.Sukiyabashi Jiro's less-than-plush surroundings notwithstanding, it is the proudpossessor of three Michelin stars, and gourmets flock to pay a minimum $300 for 20pieces of sushi chosen by the 88-year-old patron, Jiro Ono.- 'Fears of containment' -Over dinner Obama will likely try to reassure Abe that the US is focused on Asia following its foreign policy "rebalancing" eastwards, analysts say.The Middle East still draws a large measure of US attention, and the Ukraine crisishas rekindled interest in Europe. The cancellation of Obama's visit to the region last year to deal with a domestic budget battle didn't help.However, "the so-called 'pivot' or 'rebalancing' is causing more confusion andincreases tensions rather than stabilising an already dynamic region", said Wirth."It heightens fears of containment on the part of China and increases expectationsof military protection, and at times lends itself to assertive policies on the part ofsome US allies."On this trip Obama must walk a tightrope between calming Chinese fears of USencirclement and bolstering regional allies.Manila, the final leg of the tour, will be looking for reassurances from its protectorin chief.Having mounted a plucky stand over disputed South China Sea reefs against themight of Beijing, the Philippines needs to be told the US still has its back.Tokyo frets Washington may not offer wholehearted support if push came to shoveover the Japanese-controlled Senkaku islands, which Beijing claims as the Diaoyus.Historical interpretations keep muddying the Japan-China relationship, saidWashington-based international affairs analyst Taylor Washburn."The United States faces a dilemma, in that it wants to make clear its unwaveringcommitment to Japan's security in the face of destabilising behaviour by China, yetit is also frustrated by Prime Minister Abe's personal quest to efface dark episodesfrom his nation's history," he told AFP.The impounded Japanese ship row reflects anger about past injustices, while forBeijing, the squabble over the Senkakus is directly linked to Tokyo's imperialistmarch through Asia, with the islands' late 19th century "annexation" marking thestart of Tokyo's expansionism- 'Dangerous neighbourhood' -If Abe can be persuaded to rein in unpalatable views on Japan's dark past -- such asquestioning its use of wartime sex slaves in military brothels -- it could help to takesome of the heat out of the islands dispute.That same effort would also pay dividends in brokering a detente between Tokyoand Seoul, which would allow a united front against North Korean agitation, saidWashburn.It doesn't have to be a perfect peace, he added."The United States should not expect any South Korean leader to be silent in the faceof historical whitewashing," Washburn said."But if Seoul and Tokyo hold off on all security cooperation until they've come toterms over the past, Northeast Asia will be a more dangerous neighbourhood forboth countries in the meantime."After a formal summit with Abe on Thursday morning, Obama will visit Meiji Jingu,a shrine built in honour of a former imperial couple, before attending a statebanquet with the present-day head of state.He heads to Seoul on Friday. Obama is also visiting Malaysia on the week-long tour.