Reports in the American press suggest that the US troops sent to Iraq by President Obama are on the verge of entering direct combat with the Sunni militants of Islamic State in Iraq and Syria (ISIS), which controls most of eastern Syria and western Iraq.

The Washington Post reported Friday that more than 300 US troops, a mix of trainers and Special Forces operatives, were “posted at a base in the thick of a pitched battle between Iraqi forces, backed by tribal fighters, and well-armed Islamic State militants. The militants, positioned at a nearby town, have repeatedly hit the base with artillery and rocket fire in recent weeks.”

The siege is so intense that American troops are only transported in and out of the Ayn al-Asad base in Anbar Province by helicopter at night. Over the past three weeks, US and allied warplanes have carried out 13 air strikes around the al-Asad base, without being able to drive off the attackers.

The Post cited a civilian analyst suggesting that the purpose of the ISIS siege was not to overrun the al-Asad base, one of the few positions in Anbar Province still held by troops loyal to Baghdad, but rather to pin down those forces while ISIS seeks to overrun Ramadi, the provincial capital, and other strategic locations.

The New York Times, in a report on the al-Asad base published January 1, cited remarks of a US Marine Corps major there, on what the US response should be to an all-out attack on the base. “The major also said it was unclear what would happen if the air base, which is surrounded by the Islamic State, should come under attack. Should the Marines help defend the Iraqis, or flee? The small Marine compound in the vast base is under constant attack by rockets and mortars…”

Adding to the tensions among the US soldiers, according to the Times account, “is the fear of attacks from the Iraqis themselves, the ones they are supposed to train.” Such attacks have been a constant feature of the war in Afghanistan, where attacks on US-NATO forces by their Afghan “comrades” have been so frequent that they have entered into the language of the war, as “green-on-blue” incidents.

These reports come amid numerous indications that the war in Iraq and Syria, declared by Obama after the ISIS offensive in June that overran Iraq’s second-largest city, Mosul, has reached a turning point. Air strikes by the US-led coalition of NATO and Persian Gulf sheikdoms have reached a fever pitch, with dozens of strikes daily against the ISIS capital in Syria, Raqqa; on the contested town of Kobane on the Syrian-Turkish border; throughout Anbar Province in Iraq; and around Mosul, the most important ISIS conquest.

One coalition pilot, a Jordanian, was captured by ISIS after his plane was shot down near the Euphrates River in northeast Syria on December 24. The pilot has been the subject of ISIS propaganda videos but has not yet been directly threatened with beheading, like other prisoners taken by the Islamic fundamentalist group.

The Wall Street Journal reported December 31 that an Iraqi counteroffensive to retake Mosul “will be the centerpiece” of the military efforts organized under US auspices for early 2015, although the newspaper acknowledged that the Iraqi Army was a long way away from being able to mount such an effort. The Journal reported that assassination of ISIS leaders by drone-fired missiles was a key component of the planned counteroffensive.

“A senior US military official said in December that the targeting and killings of some high and midlevel Islamic State military commanders in Iraq in November and December were part of efforts to isolate Mosul and set conditions for an eventual operation to retake the city,” the newspaper reported.

The Journal also revealed that the total of US and allied “trainers and advisers” deployed in Iraq has reached 5,000, considerably higher than the figures usually cited for this effort. This includes 3,100 from the United States, with others from Canada, Britain, France, Germany and other NATO countries.

In a separate interview with the Journal on December 26, the US coordinator of the military and diplomatic campaign against ISIS, retired General John Allen, said that the US goal in Syria remains the ouster of Syrian President Bashar al-Assad, not just the defeat of ISIS.

While conceding that the US-backed “rebel” forces are too weak to remove Assad militarily, Allen said that military, diplomatic and political efforts had to be coordinated for the ultimate goal to be achieved: “And at the end of that process, as far as the U.S. is concerned, there is no Bashar al-Assad, he is gone.”

Meanwhile year-end tallies from human rights and antiwar groups suggested that the death toll in Syria in 2014 was the highest in the four-year civil war, some 76,021 people, while the death toll in Iraq was the highest since the end of the US occupation in 2011, with 17,049 civilian casualties. According to the Syrian Observatory for Human Rights, an anti-Assad, generally pro-US group, 33,278 civilians were killed in Syria in 2014, along with 22,627 government soldiers and militiamen, and 32,747 antigovernment rebels (which presumably includes ISIS as well as the US-backed groups).