As the rebels extend their reach across Iraq, Nuri al-Maliki is being urged to widen his government’s sectarian make-up or face the prospect of isolation and defeat

TWO weeks after the dramatic fall of chunks of Iraq to Sunni rebels led by the Islamic State of Iraq and Greater Syria (ISIS), a ferocious jihadist group, hostilities have simmered to a lower boil. The heat has spread, however, pulling more forces into both Iraq’s turmoil and the related war in neighbouring Syria. With no hint of progress towards a political solution or a truce, the fighting looks certain to intensify and widen, and along with it the risk of yet another humanitarian disaster on the scale of Syria, where nearly half the population has fled abroad or been displaced.

On the ground in Iraq, regular troops and Shia militiamen loyal to the Shia-dominated government of the prime minister, Nuri al-Maliki, appear to be holding a rough defensive line north of the capital, Baghdad. Kurdish Peshmerga forces also continue to secure a border that stretches some 1,000km (621 miles) across the north and east of Iraq, separating their autonomous Kurdistan from the rebellious Sunni-majority region (see map).

But the rebels controlling their northern and western zone, spearheaded by an ISIS force estimated at up to 15,000 fighters, have been bolstered by allied Sunni militias. Together they are steadily encroaching on pockets of territory still loyal to the government in Baghdad.

In some cases ISIS has persuaded local Sunni militias to declare allegiance to it. In others it has won control by force, taking such towns in Anbar province as Rutba and Qaim, which fell on June 22nd, and the larger city of Tel Afar to the north. The rebels’ strategy appears to be to consolidate control along the Tigris and Euphrates rivers to the north of Baghdad, as well as the large desert area bordering Syria, Jordan and Saudi Arabia. ISIS has also taken the desert town of Nukhaib, halfway between Baghdad and the Saudi border.

ISIS has largely succeeded in its immediate aims, though Sunni forces hostile to it still hold stretches of the Euphrates, both in Iraq and Syria. On the Syrian side, most anti-government rebels view ISIS, an ostensible ally in the fight against Bashar Assad’s regime, as a dangerous interloper bent on creating its own state rather than liberating Syria.

Syrian rebels opposed to ISIS have pointed in the past to the apparent hesitation of Mr Assad’s forces to attack ISIS as proof of its tacit co-operation with the regime to weaken other rebel groups. But the radical jihadists’ gains in Iraq, including its capture of arms and cash, are now tilting some Syrian rebel groups back towards wanting to ally with ISIS. Some local rebel militias in eastern Syria are now said to be declaring their allegiance to it.

In any case, the collapse of Mr Maliki’s forces in northern and western Iraq appears to have persuaded the Syrian government, perhaps with urgings from its close ally, Iran, to take the threat of ISIS more seriously. Iraq has hitherto provided a vital supply line to Mr Assad’s regime, but has a woefully inadequate air force.

Syria has now lent a hand. In the past two weeks its aircraft have struck repeatedly at ISIS, both inside Syria and, significantly, across the border in Iraq. On June 24th a Syrian air raid on Rutba left at least 50 people, mostly civilians, dead. A strike on June 25th against Raqqa, ISIS’s main Syrian stronghold, killed at least a dozen more. Syrian warplanes have continued to pummel areas held by other rebels, killing some 50 civilians with barrel bombs in the Aleppo region in the past few days.

As Syria entered into Iraq’s war, Israel was briefly sucked into Syria’s. On June 23rd Israeli jets blasted at least nine Syrian army emplacements in retaliation for what Israeli spokesmen described as the targeting of a car carrying Israeli citizens in the Israeli-occupied Golan Heights, killing one passenger.

The fighting also spilled into Lebanon, not for the first time during Syria’s three years of warfare. On June 20th and again on June 24th, luck intervened to prevent suicide-bombers in cars from reaching their intended targets, which appear to have been Shia areas of the country. One vehicle exploded at an isolated army checkpoint, the other at a crossroads in Beirut, Lebanon’s capital. Sunni jihadists, including ISIS, blame Lebanon’s powerful Shia militia, Hizbullah, along with copycat Iraqi Shia armed groups backed by Iran, for saving Mr Assad’s regime with its men and military aid.

That aid is part of a broader effort by Iran, the Shias’ regional power, to extend its influence across a Shia arc that includes Mr Maliki’s government. Stunned by the Iraqi army’s recent setbacks, Iran has rushed military supplies to its friends in Baghdad, reportedly including signals equipment and drones. Ironically, these now share Iraqi skies not only with friendly Syrian aircraft, but also with American ones on a similar mission to rescue Mr Maliki. American military sources say they are now flying 35 reconnaissance sorties a day as part of an emergency package that includes some 300 military advisers.

The Americans’ effort to prop up Baghdad has been tempered with pleas, among others by John Kerry, the secretary of state, for Mr Maliki to unite with his political foes. The prime minister, whose party won 92 out of 328 parliamentary seats in April’s general election, more than any other, has survived two terms in office and is seeking a third. Despite having pursued the policies that have led to the current disaster by enraging the Sunni Arab minority and alienating the Kurds, Mr Maliki appears to think he can again form a government. The backing of Syria and Iran helps, and may even convince him that a Shia army can prevail on the field. But many of his fellow Shias in Iraq now want him to go, too.

On June 25th Mr Maliki blustered on television against proposals for a “salvation” cabinet including his opponents and neutral figures. He lashed out obliquely at the Kurds, with a veiled accusation that they had plotted with Sunni Arabs to divide Iraq. That may become a reality unless Mr Maliki bows to pressure at home and abroad, and offers his political foes at least some hope of a fair compromise.