When Prime Minister Merihiro Hosokawa took office last year, his coalition government had only one reason for existence: it was committed to cleaning up the corruption spawned during 38 years of rule by the Liberal Democratic Party (LDP). But last week coalition defectors helped to defeat Hosokawa’s political-reform bill in the upper house of Parliament. He will try again before Parliament adjourns at the end of this week. If he fails, his reforms and even his government will be in deep jeopardy, and urgently needed economic stimulus could be deferred indefinitely.

Hosokawa’s best shot at remaining in power may be to send the reform bill to a parliamentary conference committee. But then he could lose face if it is watered down to garner crucial support from the LDP. If Hosokawa refuses to compromise, he may have to run again under the current rules, which favor the power brokers. Either way, his political clout will be diminished.

Relations with Washington are likely to suffer. Bill Clinton saw Hosokawa as a Japanese Yeltsin, a reformer who would open up the economy. As a result, Washington cut Hosokawa considerable slack on trade issues. With a summit scheduled for Feb. 11, serious problems remain unresolved. If Hosokawa is weakened or deposed, Clinton will have to rethink his strategy for dealing with Tokyo. Any toughening of Washington’s posture will only add to the disturbing new uncertainties of Japanese politics.