David Ignatius

The regime of President Bashar Assad in Syria is facing what U.S. experts say is the most intense pressure since the early days of the four-year civil war. This new squeeze poses some stark choices for America, Russia, Iran and Syria’s neighbors.“Based on current trend lines, it is time to start thinking about a post-Assad Syria,” argues a U.S. intelligence official. Until recently, American analysts had characterized the situation there as more of a stalemate. But over the last month, rebel gains in northern and southern Syria have begun to tip the balance.

U.S. officials see mounting pressure on Assad from four directions. A potent new rebel coalition known as Jaish al-Fatah, or the Army of Conquest, backed by Turkey, Saudi Arabia and Qatar, seized the capital of Idlib province late last month. Fighting ferociously alongside this coalition is Jabhat al-Nusra, or the Nusra Front, which is affiliated with Al-Qaeda. Moderate rebels known as the “Southern Front,” backed by the United States and Jordan, are finally gaining some ground in southern Syria. And ISIS, the most fearsome group of all, is rampaging across northern, central and eastern Syria.

“Assad faces hard choices as battlefield losses mount,” the U.S. intelligence analyst says. As the pressure increases, some Assad supporters are taking precautions. Russia is reportedly evacuating some personnel from Assad’s ancestral homeland of Latakia, in northwest Syria. Meanwhile, some members of Assad’s circle are said to be seeking visas abroad and otherwise preparing for the possibility the regime may fall.

A sense of the escalating battle came in a telephone interview Thursday with Capt. Islam Alloush, the spokesman for a group known as the Islamic Army, which is coordinating with the Jaish al-Fatah coalition. Reached at what he said was a location near Aleppo, he explained that the rebels are now moving toward the two key Assad strongholds – Latakia and Damascus. “There is no doubt that the Assad army is weaker,” he said.

Alloush said his group had reports that Iran had just sent 2,000 more fighters to Syria; his report couldn’t be confirmed by U.S. officials.

But a word of caution about this “endgame” talk. Assad has seemed in trouble before, but he has been rescued by Iran and its proxies. Iranian President Hassan Rouhani seemingly doubled down this week, declaring that he stood with Assad’s government “until the end of the road.” This suggests that Tehran recognizes the new pressure but doesn’t intend to buckle. Sources say additional Iranian proxy forces have recently entered Syria to help bolster the lines.

The rebel squeeze on Assad poses some vexing problems for the U.S., too. That’s because many of the recent battlefield gains have been made by jihadi groups the U.S. regards as extremist, such as the Nusra Front and ISIS. Some officials fear that if Assad collapses, these extremist groups will rush to fill the vacuum – making the region even more unstable.

The U.S. refuses to work with the Nusra Front, regarding them as unrepentant Al-Qaeda followers, even though the group is said to receive indirect support from Turkey and Qatar. American officials weren’t persuaded by an interview broadcast last week by Al-Jazeera with Nusra Front leader Abu Mohammad al-Jolani, in which he offered conciliatory statements toward Syrian minority groups and said his fight isn’t with America.

Jolani didn’t disavow Al-Qaeda, as some had hoped, which might have opened the way for a tactical alliance. U.S. experts continue to regard him as a dangerous foe and to warn against cooperation with his fighters. This complicates planning in the north, where the Nusra Front shares operations rooms in Idlib and Aleppo with Jaish al-Fatah.

ISIS has gained so much ground in Syria and Iraq recently that some Middle Eastern strategists argue for allying now with a lesser evil, the Nusra faction and other jihadis, to stop ISIS. The logic, explains one official, is “First you defeat Hitler, then you defeat Stalin.” Other analysts argue that the only good knockout punch is Turkish military intervention, backed by U.S. air support.

The Obama administration’s focus remains a diplomatic settlement. Officials argue that Moscow and Tehran will eventually see so much pressure on Assad, from so many dangerous jihadi groups, that they will embrace negotiations for a political transition away from the current regime.

U.S. officials keep hoping for such a change of heart by Russia and Iran. But four years into this gruesome war, hope is not a strategy. The U.S., sadly, still hasn’t built a reliable, moderate force that could push Assad over the tipping point and govern Syria after he goes.