A recent surge in bombings by al-Qaida in Iraq against the Shiite-dominated government of Prime Minister Nouri al-Maliki is starting to look like an extension of the Sunni-led war in neighboring Syria against the regime of Iranian ally Bashar Assad.

But on a broader, geostrategic level, these conflicts reflect a new assertiveness by Sunnis across the Arab world to thwart Tehran's expansionist objectives.

If Tehran has its way, it will carve out a Shiite land corridor running westward across Shiite-majority Iraq to link with Syria, dominated by Assad's minority Alawite sect, an offshoot of Shiite Islam, and thus to Lebanon under the control of Hezbollah, Iran's powerful Shiite proxy sitting on Israel's northern border.

The Syrian civil war, which entered its third year Friday, and the growing strength of the opposition, increasingly dominated by Sunni jihadists from around the Muslim world, threatens to wreck Tehran's master plan for regional domination.

The al-Qaida resurgence in Iraq puts greater pressure on Maliki's shaky, Iran-leaning coalition and endangers Tehran's plans to turn historic enemy Iraq, with its vast oil and natural gas reserves, into a satellite of the Islamic Republic.

Indeed, with the Baghdad government under attack on all sides by the resurgent AQI, which is feeding seasoned fighters into Syria for the anti-Assad forces, Maliki's being forced to rely on Tehran more than he'd like.

The fall of Assad's regime, which many observers believe is becoming inevitable, will likely lead Tehran to step up its plans to ensure, following the U.S. military withdrawal in December 2011, that Iraq is locked into its sphere of influence.

"I suspect the Iranians are going to be very dismayed by the collapse of Syria ... and will redouble their efforts in Iraq," observed Kenneth Pollack of the Brooking Institution's Saban Center for Middle East Policy in Washington.

That's if Iraq can stay together long enough.

The AQI offensive in Iraq, targeting the increasingly autocratic Maliki's government and its Iranian-backed Shiite security services, as well as the majority Shiite community is putting immense strains on the post-2003 federal state.

It's raising the specter of sectarian savagery that tore the nation after the U.S. invasion, which ended decades of minority Sunni domination. Only this time around there are no U.S. forces to hold the country together.

"Sectarian strife ... which was responsible for the death of tens of thousands, is making a comeback," declared analyst Ramzy Baroud.

"Iraqi Sunnis, including major tribes and political parties, are demanding equality and the end to their disenfranchisement in the relatively new, skewed political system under Maliki.

"Massive protests and ongoing strikes have been organized with a unified and clear political message," Baroud observed.

"However, numerous other parties are exploiting the polarization in every way imaginable: to settle old scores, to push the country back to the brink of civil war, to amplify mayhem under way in various Arab countries, most notably Syria, and in some instances to adjust sectarian boundaries in ways that could create good business opportunities."

Iraq's ethnic Kurds, who are Sunnis and locked in an armed confrontation with Maliki's forces over territory and oil, are moving toward independence, possibly tying up with Syria's Kurds.

There are rumblings in Sunni regions for greater autonomy.

Every day, the Syrian war comes closer. Earlier this month, al-Qaida in Iraq killed 48 Syrian troops who fled into Iraq.

Iraqi officials estimate some 300 Islamists cross from Iraq into Syria every month, mostly to join Jabhat al-Nusra, the most powerful Islamist group fighting Assad.

The Quilliam Foundation, a London think tank that focuses on Islamist militancy, says Jabhat al-Nusra is led by AQI veterans who fought the Americans in Iraq.

That must drive Assad crazy. When the Americans were fighting in Iraq, his regime provided a "ratline" into the country for Islamist volunteers, including hundreds of Syrians, seeking to join al-Qaida's jihad.

Observers say the AQI-directed violence in Iraq will escalate as Syria's war moves toward an endgame.

"The collapse of the Assad regime would mean not just an increase in jihadist actions, but also a boost to the self-confidence of all Iraqi Sunnis," Oxford Analytica said.

"Conversely, if Iran lost its footing in Syria, it might see Iraq as its western front line, leaving open the possibility of a Sunni-Shiite confrontation there."