The Obama administration is stepping up pressure upon the US-installed regime in Iraq over its alleged complicity in what Washington says are Iranian arms shipments being flown through Iraqi airspace to Syria. The attempt to intimidate the government of Iraqi Prime Minister Nour al-Maliki is part of a broader US effort to tighten the noose around Syria. This includes the imposition of new sanctions and stepped-up support to the so-called rebels seeking to topple the regime of President Bashar al-Assad.

On Wednesday, Senator John Kerry, the Democratic chairman of the Senate Foreign Relations Committee, threatened that the US would cut off aid to Iraq if the Maliki government failed to bow to US demands that it halt Iranian overflights to Syria.

Kerry’s threat coincided with the Reuters news agency’s publication of an article based upon a report leaked by an unnamed “Western intelligence agency.” The report claiminsthat Iranian aircraft are flying both military personnel and large quantities of arms to Syria via Iraqi airspace. It also alleges that Iran is “continuing to assist the regime in Damascus by sending trucks overland via Iraq.”

“The intelligence report alleges that the extent of such shipments is far greater than has been publicly acknowledged, and much more systematic, thanks to an agreement between senior Iraqi and Iranian officials,” according to Reuters.

The Iraqi government has denied that it has allowed anything but humanitarian shipments from Iran and says it is opposed to the delivery of weapons to either side in the conflict.

Kerry’s threat came in the context of a foreign relations committee hearing on the nomination of Robert Beecroft as the next US ambassador to Baghdad. Beecroft, currently the deputy chief of mission in Iraq, testified that he and other US officials had demanded that the Maliki government halt the alleged Iranian overflights.

“Maybe we should make some of our assistance or some of our support contingent on some kind of appropriate response,” Kerry said. “It just seems completely inappropriate that we’re trying to help build democracy, support them, put American lives on the line, money into the country, and they’re working against our interest so overtly.”

These remarks express the bitterness and anger within the US ruling establishment over the debacle that resulted from the US war and occupation of Iraq, which were carried out not to “build democracy” or “support” the Iraqi people, but to assert US hegemony over the vast energy reserves of the Persian Gulf.

US efforts to subdue the country cost an estimated one million Iraqi lives. Part of this carnage was the result of a divide-and-rule strategy that pitted Iraqi Shias against Sunnis in a horrific sectarian civil war.

The Maliki regime, dominated by predominantly Shia parties, now fears that the same process is being unleashed in Syria, where Washington and its allies are backing sectarian Sunni militias in an attempt to topple Assad, who heads a secular regime dominated by the Alawite minority, an offshoot of Shiism.

Iraq has seen an escalation of terrorist attacks by Sunni Islamist militants, emboldened by the support given to their cohorts across the border in Syria. The government fears that Assad’s ouster and the coming to power of a Sunni regime in Syria will reignite a civil war in Iraq itself.

The regional spillover of the imperialist-backed war for regime-change in Syria has also become increasingly evident on the Syrian-Turkish border, where “rebels” have in recent days overrun three border posts and asserted their control over a growing swathe of rural areas in northern Syria.

While fighting has reportedly continued between the anti-Assad insurgents and Syrian army forces in these areas, the control of the border crossings would facilitate the shipment of arms, money and foreign fighters into Syria, which is being coordinated by the Turkish, Saudi and Qatari governments, with CIA agents in place to oversee the operation.

Insurgent control of the territory in northern Syria also sets the stage for the establishment of some kind of a “humanitarian safe zone” on Syrian soil, as the Turkish government has advocated, providing a launching pad for more direct imperialist intervention.

Complicating these aims, however is the crisis within Turkey itself over the Syrian intervention, with growing indications that the Turkish people have turned against the government’s policy, which is widely seen as serving as an instrument for US imperialist interests.

Antakya, the capital of the southeastern Turkish province of Hatay, saw over 5,000 demonstrators take to the streets on Sunday demanding an end to Turkey’s role in the Syrian intervention. Chanting “Muslims are friends” and “We want peace, not war,” the demonstration tapped into increasing resentment over the breakdown of cross-border trade as well as the presence in the province of some 80,000 Syrian refugees crowded into camps along the border. Some 2,000 riot police were brought into the city to break up the demonstration with tear gas and water cannon.

Also fueling popular Turkish hostility to the Syrian intervention is the sharp uptick in clashes between Turkish security forces and the separatist guerrillas of the Kurdish PKK (Kurdistan Workers Party).

The country’s mountainous southeastern region has seen some of the fiercest fighting since the 1990s. An ambush of an army column on September 18 left 10 Turkish soldiers dead. The attack came just two days after a mine blew up a minibus, killing eight police. The day before that, a similar blast killed four soldiers. The government has retaliated by sending fighter jets and attack helicopters to bomb Kurdish areas. Prime Minister Recep Tayyip Erdogan recently claimed that the army has killed 500 PKK fighters since February.

Reuters reports that the Erdogan government “has called on domestic media to limit their coverage of PKK attacks on soldiers.” It cites a cartoon in the opposition Cumhuriyet newspaper, showing the prime minister reading a blank newspaper and saying, “There’s no news or analysis, just as I wanted it.”

It is widely recognized within Turkey that the escalation of this internal conflict is bound up with the Syrian intervention and the sharp deterioration of relations between Ankara and its neighbors, Syria, Iraq and Iran, all of which have substantial Kurdish populations. In particular in Syria the Western-backed insurgency has forced the Syrian army to abandoned sparsely populated areas of the north which have been taken over by Kurdish militias, some of which have close ties to the PKK.

The “rebel” offensive in the border area has brought elements of the so-called Free Syrian Army (FSA) into close proximity to these Kurdish-controlled districts. This has led to armed clashes in which the FSA suffered casualties.

The Obama administration on Wednesday imposed new sanctions relating to the Syrian conflict, targeting companies in Belarus and Iran which it claims have supplied weapons and communications equipment to the Assad government—the same type of supplies that Washington and its allies are shipping to the “rebels.”

These are only the latest in a series of unilateral US measures aimed at crippling Syria’s economy and blocking supplies for its military.

Meanwhile, a series of reports have come out warning of the increasingly dominant role being played in the Syrian “revolution” by Sunni Islamist forces, as well as foreign fighters with links to Al Qaeda.

The United Nations Human Rights Council issued a report Monday condemning repression by the Syrian government, but also cited an “increasing and alarming presence” of foreign Islamist militants in Syria, who it said act to “push anti-government fighters towards more radical positions” and are responsible for human rights violations.

The Swedish Institute for International Affairs has issued a report warning of the “Islamization” of the Syrian civil war. The sectarian character of the conflict, it says, “benefits jihadis by creating demand for their brand of violent Sunni chauvinism.” It adds, “The second factor is the foreign support pouring from regional governments and non-state organizations, which is disproportionately empowering Islamist groups.”