Amid the mess, a new phase in Muslim civil war

The U.S. shoots down a Syrian fighter-bomber.

Iran launches missiles into eastern Syria.

Russia threatens to attack coalition aircraft west of the Euphrates. What is going on? It might appear a mindless mess, but the outlines are clear. The great Muslim civil war, centered in Syria, is approaching its post-Islamic State phase. It’s the end of the beginning.

The parties are maneuvering to shape what comes next.

Everyone knows that the Islamic State is finished. Not that it will disappear as an ideology, insurgency and source of continuing terrorism both in the region and the West. But it will disappear as an independent, organized, territorial entity in the heart of the Middle East.

It is being squeezed out of existence. Its hold on Mosul, its last major redoubt in Iraq, is nearly gone.

Raqqa, its stronghold in Syria and de facto capital, is next. When it falls — it is already surrounded on three sides — the caliphate dies.

Much of the fighting today is about who inherits. Take the Syrian jet the U.S. shot down. It had been attacking a pro-Western Kurdish and Arab force not far from Islamic State territory.

Why? Because the Bashar Assad regime, backed by Iran, Hezbollah and Russia, feels secure enough to set its sights on eastern Syria.

If it hopes to restore its authority over the whole country, it will need to control Raqqa and surrounding Islamic State areas.

But the forces near Raqqa are pro-Western and anti-regime. Hence the Syrian fighter-bomber attack.

Hence the U.S. shootdown. We are protecting our friends. Hence the Russian threats to now target U.S. planes. The Russians are protecting their friends.

For Iran, Syria is the key, the central theater of a Shiite-Sunni war for regional hegemony. Iran (which is non-Arab) leads the Shiite side, attended by its Arab auxiliaries — Hezbollah in Lebanon, the Shiite militias in Iraq and the highly penetrated government of Iraq, and Assad’s Alawite regime.

Arrayed on the other side of the great Muslim civil war are the Sunnis, moderate and Western-allied, led by Saudi Arabia, the Gulf states, Egypt and Jordan — with their Great Power patron, the United States, now (post-Obama) back in action.

Imagine the scenario: a unified Syria under Assad, the ever more pliant client of Iran and Russia; Hezbollah, tip of the Iranian spear, dominant in Lebanon; Iran, the regional arbiter; and Russia, with its Syrian bases, the outside hegemon.

Our preferred outcome is radically different: a loosely federated Syria, partitioned and cantonized, in which Assad might be left in charge of an Alawite rump.

The Iranian-Russian strategy is a nightmare for the entire Sunni Middle East. And for us, too. The Pentagon seems bent on preventing it. Hence the Tomahawk attack for crossing the chemical red line. Hence the recent fighter-bomber shootdown.

A reasonable U.S. strategy, given the alternatives. But not without risk. Which is why we need a national debate before we commit too deeply.

Perhaps we might squeeze one in amid the national obsession with every James Comey memo-to-self ?