Prime Minister Shinzo Abe will visit Iran next week in hopes of engineering a diplomatic breakthrough that will thaw the icy U.S.-Iran relationship. Having maintained cordial if not friendly relations with Iran despite the growing irritation and anger of other Western nations, Abe hopes to meet Iran's President Hassan Rouhani and the country's supreme leader, Ayatollah Ali Khamenei, during his stay in Tehran. Those meetings are likely to materialize, but a meeting of the minds is not: Both sides are too entrenched and the changes demanded are too great. The prime minister's effort is to be encouraged, nonetheless.

Japan has long internalized a tension in its relations with Iran. Tokyo has called for engagement, befitting its belief that diplomacy is the best way to address regional problems, as well as its dependence on Middle Eastern oil; at one point in the past, it imported 70 percent of its oil from Iran, and today Japan gets 85 percent of its oil and 28 percent of its natural gas from the Persian Gulf. At the same time, however, Tokyo must be sensitive to U.S. concerns, given the bilateral security alliance and the hostility that has dominated that relationship since the Iranian Revolution and the taking of American hostages in 1979.

The administration of U.S. President Donald Trump has amplified tensions in the relationship by withdrawing from the Joint Comprehensive Plan of Action (JCPOA), the multilateral agreement that capped Iran's nuclear program, and then pursuing a "maximum pressure" campaign that puts the squeeze on Iran (and its trading partners) with unilateral sanctions that aim to force Tehran to change its behavior across a range of concerns. In recent weeks, the United States has sent military assets, including aircraft carriers and bombers, to the region and warned Tehran that it faces a military response if Iran or its proxies threaten the U.S., its assets or partners in the region.