As Syrian government forces, with help from Iran and Russia, mount an offensive to drive rebel groups from their strongholds in the southwestern part of the country, and the rebels counterattack, fighting has intensified in Quneitra just over the border from the Israeli Golan. Last weekend, ten Syrian mortar and tank shells—aimed at rebel troops along the border—landed in Israel, causing the IDF to respond by attacking Syrian positions. Ron Ben-Yishai explains:

[T]he Syrian army tossed aside all of its rules of caution and fired at the rebel forces that attacked it without considering the fact the fire could spill over into Israel. The Syrian army usually avoids firing into Israeli territory, knowing how rapidly and aggressively Israel will respond, as part of its policy not to allow any fire into, or violation of sovereignty on, its territory.

This Israeli policy stems from the understanding that failure to respond aggressively to any spillover into Israeli territory, even an unintentional spillover, will be interpreted as a violation of Israeli sovereignty and could turn from a drizzle into a flood, not to mention wearing out the Israeli deterrence in the Golan Heights. Israel, therefore, has made it a point to respond. . . .

Saturday’s errant fire was unusual in two aspects: first, it included an unusual number of mortar shells and tank projectiles that landed in an open area in Israel, as opposed to the usual spillover of one or two mortar shells. Saturday’s incident also included direct tank fire, and the shooters were perfectly aware of the fact the shells would hit Israeli territory.

Second, there were thousands of Israeli travelers in the Golan Heights when the Syrian mortars were fired, and they could have gotten hurt. The Syrians, who are watching our area at all times, were aware—or at least should have been aware—of that fact, which is why the Israeli response was unusually severe.

On the same day the cease-fire went into effect along the Israel-Lebanon border, rebel forces launched an unexpected offensive, and within a few days captured much of Aleppo. This lightening advance originated in the northwestern part of the country, which has been relatively quiet over the past four years, since Bashar al-Assad effectively gave up on restoring control over the remaining rebel enclaves in the area. The fighting comes at an inopportune moment for the powers that Damascus has called on for help in the past: Russia is bogged down in Ukraine and Hizballah has been shattered.

But the situation is extremely complex. David Wurmser points to the dangers that lie ahead:

The desolation wrought on Hizballah by Israel, and the humiliation inflicted on Iran, has not only left the Iranian axis exposed to Israeli power and further withering. It has altered the strategic tectonics of the Middle East. The story is not just Iran anymore. The region is showing the first signs of tremendous geopolitical change. And the plates are beginning to move.

The removal of the religious-totalitarian tyranny of the Iranian regime remains the greatest strategic imperative in the region for the United States and its allies, foremost among whom stands Israel. . . . However, as Iran’s regime descends into the graveyard of history, it is important not to neglect the emergence of other, new threats. navigating the new reality taking shape.

The retreat of the Syrian Assad regime from Aleppo in the face of Turkish-backed, partly Islamist rebels made from remnants of Islamic State is an early skirmish in this new strategic reality. Aleppo is falling to the Hayat Tahrir al-Sham, or HTS—a descendant of Nusra Front led by Abu Mohammed al-Julani, himself a graduate of al-Qaeda’s system and cobbled together of IS elements. Behind this force is the power of nearby Turkey.