The U.S. attacked and killed Maj. Gen. Qassem Soleimani, the commander of Iran’s Islamic Revolutionary Guard Corps, which is directly under the control of Ayatollah Ali Khamenei, the country’s supreme leader.

Tehran declared that it will withdraw from the nuclear deal with European nations and enrich its stockpile of uranium without limitations. This swiftly raised tensions between the U.S. and Iran.

If the situation escalates into a large-scale conflict, it will seriously damage peace and stability not only in the Middle East region but in the whole world. The U.S. and Iran, of course, and the international community including Japan must do their utmost to prevent the current situation from escalating into a conflict.

Pro-Iranian militias are continuously taking provocative actions against the U.S. and Israel including terrorism in Lebanon, Syria and Iraq. It is believed that the “Quds Force,” a unit of the Islamic Revolutionary Guard Corps, which was led by Gen. Soleimani, has supported these provocative actions behind the scenes.

At the end of last year, U.S. forces stationed in Iraq were attacked by a militia, killing an American contractor. From the U.S.’s viewpoint, the killing of Gen. Soleimani was probably unavoidable to protect the safety of Americans.

It should not be overlooked that President Donald Trump has clarified that he will no longer condone Iran’s actions that threaten the United States.

Terrorist acts staged by Tehran-backed militias are a major source of instability in the Middle East. It has been pointed out that Iran has been involved in attacks on tankers and seizures of vessels that threaten the freedom of navigation.

The U.S. has designated the Islamic Revolutionary Guard Corps, which is regarded as a quasi-military, as a “terrorist organization.” Rather than threaten the U.S., Iran must sever its ties with insurgents across the region. If Tehran claims that it was not involved in attacks on tankers, the country must prove it.

Most worrisome is the growing danger of war as a retaliatory measure against the U.S. as the people of Iran regard Gen. Soleimani as a hero. Iranian President Hassan Rouhani publicly vowed revenge. In response, President Trump said that the U.S. will respond with fierce attacks.

Since May last year, Iran has indicated it will gradually withdraw from the nuclear deal. The latest announcement of withdrawal is its fifth. The nuclear deal seems to be on the verge of unraveling. The international community must urge Iran to restrain itself from taking retaliatory measures and return to the nuclear deal.

The leaders of the UK, France, and Germany issued a joint statement calling for Iran’s adherence to the nuclear deal and the suspension of violence. As Japan has strong connections with both the U.S. and Iran, Tokyo can play an important role in mitigating tensions. Japan should actively be involved as a mediator.