SYMBOLIC gestures are the tools of any leader’s trade, but nowhere do they spell the difference between life and death quite like the Middle East. For example, the visit in 2000 by Ariel Sharon, the former Israeli prime minister, to Temple Mount in Jerusalem, the site of two Islamic shrines, helped set off the second intifada.

Thus when Pope Benedict XVI visits Jordan, Israel and the Palestinian territories starting on Friday, the world may be excused for holding its breath. In his four years on the job, this pope has not always demonstrated a deft symbolic touch. If he simply manages to get back to Rome without starting a war, some might declare the trip a success.

Yet Benedict can, and should, do much more. Granted, the pope is not a politician, and this trip is more a pilgrimage than a diplomatic mission. Nonetheless, Benedict can make a unique contribution to the peace process at a moment when it obviously needs the help.

The reason for this is that popes enjoy a tremendous advantage over Western politicians in engaging the Middle East. This is the realm of “theopolitics,” where religious convictions always shape policy choices. A pope can engage those convictions in a way that secular trouble-shooters like former Senator George Mitchell, President Obama’s envoy to the Middle East, never could.

To be sure, Benedict doesn’t have the same reputation as a healer that his predecessor, John Paul II, had. The late pope was seen as a friend of both Jews and Muslims, while Benedict has had problems with both faiths. Diplomatically speaking, however, that’s far preferable to being perceived as a nemesis to one or the other. Even Benedict’s recent run of bad press in the West stemming from his comments on condoms and AIDS has an upside. It may make him a more sympathetic figure for devout Jews and Muslims, who know what it’s like to be on the wrong side of Western secular taboos.

If he plays his cards right, Benedict could move things forward in four ways.

First, the pope can emphasize that the “two-state solution” to the Israeli-Palestinian conflict reflects a global moral consensus. He arrives at a moment of growing despair, after the new Israeli government seemed to cast doubt on its commitment to Palestinian statehood. Wielding the bully pulpit of the papacy, Benedict can stress that respecting the natural right of Palestinians to sovereignty isn’t about statecraft but about justice.

Yes, while in Israel Benedict will have to mend fences after his controversial decision in January to lift the excommunication of a Holocaust-denying bishop. He should not allow damage control, however, to blur his message about the urgency of a just peace.

Second, Benedict can insist that the Palestinians reject extremist elements within their leadership — an application of his broader push for a reformed Islam that respects both faith and reason. On that front, the pope has momentum. Since he angered Muslims in 2006 by citing a Byzantine emperor with nasty things to say about Muhammad, Benedict has improved his pitch, suggesting that Christianity and Islam ought to be natural allies against forms of secularism hostile to religion. Last month, for example, the Vatican signed a memorandum of understanding with the Arab League.

Benedict can now spend some of that capital, pressing Palestinians to embrace religious freedom, and Israel’s right to exist, as the price of admission to any Christian-Muslim partnership.

Third, Benedict can energize support for Christians in the Holy Land, who are poised on the brink of extinction. During the British mandate in Palestine, Christians were around 20 percent of the population; today they’re under 2 percent because of tremendous emigration.

Historically, Arab Christians have promoted a pluralistic vision of society, standing between resurgent Islamic fundamentalism and ultranationalist strains in Judaism. If they disappear, prospects for peace become dimmer. The pope must assure these believers that global Christianity will not abandon them.

Fourth, Benedict can advance the end game of the peace process by urging the leaders he meets with to bring Iran on board in all regional discussions. The Vatican has been holding talks with Iran’s Islamic Culture and Relations Organization, a government-affiliated body, for two decades. Moreover, Roman Catholicism and Shiite Islam, which dominates Iran, have a natural affinity: a strong clerical hierarchy, popular devotions and saintly intercessors, and a core theology of martyrdom. Benedict could open the door, leaving it up to the Iranians to walk through.

In the Middle East, religion is either part of the problem or part of the solution. The drama of the pope’s voyage comes down to which way he nudges things along.