It was not only Operation Tomodachi, however, that helped to drive the U.S. and Japan back together. In September 2010, a Chinese fishing boat rammed a Japanese patrol boat in the waters off of the Senkaku Islands that lie south of Okinawa in the East China Sea. This was the first incident in what would become an increasingly volatile dispute between the Japan and China over who owns the islands (known as the Diayou Islands in China). The saber rattling between Japan and China continues, and has escalated to the point where there are very real fears that a misstep by either side could lead to a war.

One side effect of this dispute has been to push the Japan away from China, and towards the U.S. This movement was already well underway when the LDP returned to power at the end of 2012. Nevertheless, the new LDP Prime Minister, Abe, announced that restoring relations with the U.S. would be a top priority. Indeed, he wanted his first visit abroad to be to the U.S. The visit was delayed, however, ostensibly because of White House preparations for the president's second inauguration, but probably also because of a new issue that had emerged between Japan and the U.S.: Japanese participation in the Trans-Pacific Partnership (TPP).

The TPP is a potential trillion-dollar free trade agreement between the Pacific-facing nations of Brunei, Chile, New Zealand, Singapore, Australia, Peru, Malaysia, Vietnam, the United States, Mexico, and Canada. President Obama mentioned the TPP during his recent State of the Union address, and it lies at the center of the Obama administrations much-touted "Asia pivot." Nevertheless, as it now stands, the U.S. already has free trade agreements with six of 10 countries that are parties to the TPP negotiations, including almost all of the larger economies. Therefore, it is difficult to see why the TPP is expected to have such a great impact on U.S. trade or U.S. relations with Asia. This would change, however, if Japan were to become part of the TPP. For the first time, the U.S. and Japan, the first and third largest economies in the world, would be joined by a free trade agreement.

Groups like the U.S. Chamber of Commerce and the politically powerful organization of Japanese businesses known as the Keidanren strongly support Japan joining the TPP talks. The U.S. auto industry, however, worries that if Japan was to become part of the TPP, then tariffs currently placed on cars and trucks imported from Japan would have to be eliminated. Opposition is even stronger among Japanese farmers, who do not want their country to enter into an agreement that would potentially end the extraordinary tariffs that now protect much of Japanese agricultural from foreign competition.

Although Abe had given indications that he supported entry into the TPP negotiations, he had to be mindful that rural voters were crucial to the LDP's return to power. That is why there was speculation in Japan that the Obama administration delayed Abe's visit because they wanted the new Prime Minister to have a clear position on the TPP. In fact, the situation with the TPP was beginning to exhibit shades of earlier dispute over the Futenma bases, when at one point President Obama was said to have asked if then Prime Minister Hatoyama could "follow through" with his commitments on moving the Okinawan bases. In fact, it began to seem reasonable to expect that there would be no movement at all on the TPP issue during the meetings in Washington.