JUNICHIRO KOIZUMI will soon arrive in Washington for what is probably his last official visit to the United States as Japan's prime minister. While in Washington, Koizumi will seek to cement the progress made in the bilateral relationship during his 6-year tenure. Yet, although Washington and Tokyo are expected to use the occasion to tout progress on nearly all major strategic questions, the two allies will almost certainly remain silent on one pressing issue: Taiwan's increasingly uncertain role in their East Asian security architecture.

Both Washington and Tokyo are worried about China's growing military capabilities. This concern was voiced mutually in February 2005, when Condoleezza Rice, Donald Rumsfeld, Japan's Minister for Foreign Affairs Nobutaka Machimura, and Minister of Defense Yoshinori Ohno agreed to make "peaceful resolution" of the Taiwan issue a "common strategic objective." And it was amplified by the Pentagon's recently-released report to Congress on Chinese military power, which stressed that "the cross-Strait military balance is shifting in the mainland's favor" and that "Beijing's sustained military buildup in the area of the Taiwan Strait risks disrupting the status quo."

So far, the Bush administration has been seeking to defuse the danger through constructive engagement with Beijing. The White House has encouraged China to accept policies supportive of current international institutions and frameworks through mechanisms like Deputy Secretary of State Robert Zoellick's Senior Dialogue. The rationale of this approach, as Zoellick explained last September, is that greater cooperation from China is essential to the smooth functioning of the international economy. "Responsible stakeholders recognize that the international system sustains their peaceful prosperity, so they work to sustain that system," he said.

But progress on Taiwan's status has been conspicuously absent. Beijing's claims to the island make it the primary Sino-American flashpoint; and thus a topic that U.S. diplomats prefer to avoid. Washington's policies vis-à-vis these claims are based upon three Joint-Communiqués with Beijing and the legally binding Taiwan Relations Act--documents that provide a secure, if often ambiguous, framework for U.S. strategy. But while these documents dictate the Taiwan Strait remain frozen in a political "status quo" the world around it is changing.

Unfortunately, U.S. policy has been slow to adapt. "There is a tendency by senior U.S. officials to view Taiwan largely through the prism of U.S.-China relations, rather than as a bilateral relationship that stands on its own merits," says former Deputy Assistant Secretary of State Randall Schriver. "When defined this way, there are often sacrifices in U.S.-Taiwan relations."

Within the administration there are differing views about whether Beijing's policies toward Taiwan reflect its broader regional security stance. One camp tends to view China's military buildup in the Taiwan Strait as unique and not indicative of a larger regional strategy. The other fears that the shifting military balance between Beijing and Taipei could eventually "pose credible threats to other modern militaries operating in the region," as Assistant Secretary of Defense Peter Rodman told the U.S.-China Economic and Security Review Commission last March. Both arguments are reasonable, but are also mutually incompatible. The result has been a disjointed U.S.-Taiwan policy that risks undermining America's long-established strategy in the Taiwan Strait.

TAIPEI MAYOR MA YING-JEOU'S March visit is a case in point. Ma is chairman of the pro-unification Kuomintang (KMT) party and its top candidate to challenge the ruling Democratic People's party's (DPP) in the 2008 presidential elections. Washington rolled out the red carpet for Mayor Ma and arranged meetings with top-level U.S. officials.

The Harvard-educated Ma cut a fashionable figure in Washington. But his support for closer economic integration with the mainland and his wariness of Japan mean that if elected, his policy choices could upset Washington and Tokyo. In April, for instance, Ma's predecessor led a delegation of KMT lawmakers and businessmen to Beijing, met with President Hu Jintao and signed a joint statement.