The region´s Sunni-led powers are appearing more confident, encouraged by the prospect that the Sunni-led rebellion could bring down Syrian President Bashar al-Assad´s regime • Iran and Hezbollah have seen their reputations and Shiite influence damaged by their support for Assad in the face of the uprising.

Not long ago, Arabs everywhere listened when the leader of Hezbollah spoke. Sheik Hassan Nasrallah´s prominence, bolstered by his Lebanese terrorist organization´s battles against Israel, was a sign of the rising regional influence of Shiite Muslims and overwhelmingly Shiite Iran. Now, his speeches don´t necessarily make front pages even in Lebanon.

The change is emblematic of how the bloody conflict in Syria, now in its 18th month, has brought a shift in the Middle East´s sectarian power balance. For much of the past few years, Shiites were surging in power across the region, based on the central alliance between Iran, Syria and Hezbollah, with close relations to Shiites who took power in post-Saddam Hussein Iraq.

But now the region´s Sunni-led powers are appearing more confident, encouraged by the prospect that the Sunni-led rebellion could bring down Syrian President Bashar Assad´s regime, dominated by members of the Shiite offshoot sect of Alawites. Assad´s fall would cost Iran a priceless foothold in the heart of the Arab world. Hezbollah would lose a bastion of support and a conduit via Syria for vital Iranian weapon supplies.

Already, Iran and Hezbollah have seen their reputations damaged by their support for Assad in the face of the uprising.

"Iran´s influence in the Arab world has taken a big hit recently," said Alireza Nader, a Middle East expert from the Rand Corporation. Iran´s and Hezbollah´s support of the Assad regime, he said, contradicts their support for Arab Spring revolts elsewhere. "This policy makes Iran, and Hezbollah, appear cynical if not hypocritical."

Further boosting the Sunnis, the wave of uprisings around the Middle East since early 2011 brought greater political influence to Sunni Islamists, particularly the Muslim Brotherhood, in Egypt and Tunisia.

The announcement Saturday that Egypt´s new, Muslim Brotherhood-rooted president, Mohammed Morsi, will visit Iran on Aug. 30 — the first such visit by an Egyptian leader since the mid-1970s — likely reflects the growing confidence that Iran´s status is damaged and that Sunni Arab nations can steer the agenda.

Egypt has long shunned Iran, and in recent years, former President Hosni Mubarak had joined with Sunni powerhouse Saudi Arabia in touting Tehran´s growing influence as the main threat to the Middle East. Morsi, who was elected this year in the wake of Mubarak´s ouster, has called for Assad´s removal and last month pledged Egypt´s "protection" of what he called Saudi Arabia´s "guardianship" of Sunni Islam against outside threats, a thinly veiled reference to Iran.

But at the same time, Morsi´s Brotherhood has suggested it is aiming for a new policy of engaging with Iran and influencing it. During a recent visit to Saudi Arabia, Morsi proposed the formation of a contact group of Egypt, Saudi Arabia, Iran and Turkey to mediate a solution in Syria. The proposal may have been largely symbolic, but Brotherhood officials touted it as a return of Egypt´s regional impact "that it had lost under Mubarak."

"Sunni Arab countries are pushing back to make up for the losses they suffered after 2003," said prominent Iraqi analyst Hadi Jalo. "With the civil war in Syria and the isolation of the government in Iraq, the Shiite tide is retreating."

The "Shiite bloc" has suffered a number of reversals amid the Syria conflict.

The Palestinian terrorist group Hamas moved its political leadership out of the Syrian capital Damascus, costing Assad the leverage he had long enjoyed by hosting the group. Now Hamas, which had long received Iranian largesse, has shifted allegiances to energy-rich Qatar, which is also a backer of Syria´s opposition.

Iraq, where the Shiite majority rose to power following Saddam Hussein´s 2003 ousting, is firmly in Iran´s sphere of influence, but the Shiite-led government there is isolated, facing serious challenges to its authority from the Sunnis and Kurds, who between them cover some 40 percent of the population.

Attacks blamed on Sunnis there have further eroded the government´s authority. Sunni-led Arab nations, particularly Saudi Arabia and Qatar, continue to shun the Baghdad government because of its ties with Iran and its perceived marginalization of Iraq´s Sunnis.

Saudi Arabia and its Gulf allies last year also banded together to help crush an uprising by Bahrain´s Shiite majority demanding greater rights under the tiny Gulf island nation´s Sunni leadership. The uprising — which threatened to turn into an Arab Spring-style revolt — raised Saudi fears of greater Iranian influence on the doorstep of eastern Saudi Arabia, site of much of its oil resources and the center for its Shiite minority.

Iran is also facing increased pressure over its nuclear program, which the U.S. and its allies believe is intended to produce nuclear weapons. Tehran denies the charge. The U.S. has hiked up sanctions, hitting Iran´s vital oil revenues and straining its economy. Israel has talked of military strikes against Iran´s nuclear facilities.

The Shiite militant group Hezbollah, meanwhile, still holds a dominant position in Lebanon. But even that is being challenged.

Only a few years ago, Hezbollah´s leader Nasrallah had emerged as a hero even among many Sunnis across the Middle East after his fighters battled Israel to a near stalemate in a destructive 2006 war in southern Lebanon. But his backing for Assad has tainted him among many across the region, and among opponents at home. Regional news channels like Al-Jazeera no longer carry his speeches live and in full as they once did.

Nasrallah, perhaps in search of relevance, warned on Friday in an 80- minute speech of a harsh and punishing response by Iran if it were attacked by Israel. He warned that if Israel should attack Lebanon, his group with its rocket arsenal could turn the lives of millions of Israel to "real hell."

Rami Khouri, director of the Issam Fares Institute of Public Policy and International Affairs at the American University of Beirut, says Hezbollah is no doubt making preparations for survival without Assad to support it.

"Hezbollah has to face a really huge challenge if the Syrian regime falls, but I cannot imagine a group like Hezbollah waiting for this to happen and not actively preparing itself for that eventuality," he said. "But it is clear that both Hezbollah and Nasrallah have lost some stature as a result of the Syrian conflict."