We welcome President Obama’s choice of George Mitchell to be his new Middle East envoy. It is an unenviable and essential job.

A former Senate majority leader, Mr. Mitchell has the stature to represent the new administration. He negotiated the 1998 Good Friday accord in Northern Ireland, good training for taking on the Israeli-Palestinian conflict. As a Lebanese-American, his appointment also sends an important signal that the United States will continue to be an unwavering ally of Israel but also sensitive to the Palestinians’ many legitimate grievances.

His report on a failed Israeli-Palestinian cease-fire pact, produced in 2001 at former President Bill Clinton’s request, suggests Mr. Mitchell’s even-handed approach. It urged the Israeli government to freeze construction of new settlements and stop shooting at unarmed demonstrators, and Palestinians to prevent terrorist attacks and punish the perpetrators. That advice remains sound.

We fear Mr. Mitchell will find the situation even more difficult today. Eight years later, Hamas is in control of Gaza and shows no interest in making peace with Israel. The Palestinian Authority president, Mahmoud Abbas, who controls the West Bank, is committed to a two-state solution but has been dangerously weakened by Israel’s invasion of Gaza.

One of Mr. Mitchell’s first tasks will be to find ways both to lessen the suffering of Gazans and bolster Mr. Abbas. To succeed, Mr. Mitchell will need strong support from President Obama and, we hope, a good relationship with a new Israeli prime minister who is fully committed to a two-state solution.

It is a tough job. We wish him luck.