Though dramatic, the move comes as little surprise since Middle East experts and Western policymakers have been quite aware of the worsening Saudi-Iranian discord and the threat posed to Saudi Arabia by the unstable situation in Yemen, where Iran-backed Shiite Houthi rebels overran the capital of Sanaa in September, then seized the presidential palace in January and forced the abdication of President Abdu Rabu Mansour Hadi.

Wednesday’s announcement of an Arab coalition came on the same day as Hadi finally fled the country altogether after having installed his government in the port city of Aden, according to Hot Air. His exit suggests that there are now virtually no domestic barriers to the further dominance of the country by the Houthi, which have been described by some analysts and some Iranian officials as a Yemeni version of the Iran-controlled Hezbollah paramilitary in Lebanon.

But although some Iranians have privately made this boast, the official government position remains that Iran is not backing the Houthi. It seems, however, that no informed source believes this. And the official narrative is certainly undermined by the rhetoric that Iran has proffered in response to the new coalition bombing campaign.

The Iranian foreign ministry decried Saudi “aggression” in Yemen and asserted that the bombing campaign would “kill opportunities for peaceful resolution of the crisis” and would “lead to spread of terrorism and extremism in the region,” according to Arutz Sheva. But the Houthi ascendancy has already led to the growth of terrorism both on the Houthi side and among its non-governmental rivals. Attacks by Sunni militants affiliated with Al Qaeda in the Arabian Peninsula, generally considered to be the most dangerous branch of Al Qaeda, have increased in retaliation against the growth of Shiite power.

Meanwhile, Yemen has ceased to function as a stable base of US counter-terrorist actions against AQAP and other militants, and last week the last US personnel were evacuated from Yemen. To make matters worse, Town Hall reports that the American egress has allowed some US intelligence files to fall into the hands of the Houthi and by extension into the hands of their Iranian backers.

Town Hall also notes that some such files are believed to have been handed directly to Iranian advisors on the ground in Yemen, by local officials sympathetic to the sectarian cause. This is certainly a defining feature of the conflict, albeit one that is being downplayed by Tehran.

Al Jazeera quotes top Iranian officials as saying that the Saudi coalition bombing campaign threatens to cause the fighting in Yemen to spill over into other countries in the region. But for many analysts who recognize the sectarian nature of that conflict, the fighting is already difficult to differentiate from conflicts in other areas where Iran has extended its Shiite influence and given backing to sectarian militias and paramilitaries.

As Hot Air pointed out on Thursday, when the Yemeni crisis is put in context with the Iran-led conflicts against the Islamic State in Iraq and Syria, wherein brutal reprisals are taking place against both Sunnis and Shiites, “the outlines of a vast, region-wide sectarian conflict are perfectly visible.”

And the close linkages among these different war-torn regions help to complicate the current US policy of privileging different sides in each case. Town Hall notes that in addition to likely providing Iran with information about Yemeni assets and US counter-terrorism plans, the loss of intelligence files to the Houthi makes it more difficult for the US to support the Saudi coalitions missions with American drone flights.

Nonetheless, the US is tentatively backing the side of that conflict that is working to reinstall President Hadi to Sanaa. Yet at the same time, NBC News reports that American aircraft have now begun striking Tikrit in Iraq, where Iranian-led forces have been engaged in a lengthy siege of the city as they attempt to retake it from Islamic State forces. This puts the US squarely on the side of Iran in one arena but against it in another.

Expressing greater concern over the rise of Islamic State power than over the expansion in power of the Islamic Republic of Iran, the US has been tolerating Iranian interventionism in Iraq for months, all while denying that the US and Iran are actually coordinating their military activities. But the US is not oblivious to the dangerous of Iranian hegemony, as evidenced by the fact that American forces had delayed for upwards of a week before contributing airstrikes to the siege of Tikrit, where an Iranian and Iraqi victory could lead to the further empowerment of Tehran-franchised Shiite militias beyond the borders of Tehran.

But NBC News adds that the US was simultaneously worried that withholding air support could have given Iraqis the impression that Iran is a more reliable partner than the US. The dilemma may suggest that US policymakers feel that they are stuck between a rock and a hard place as they try to utilize Iranian power against mutual enemies while also constraining Iranian growth to a degree that does not dramatically increase the threat to American interests.

While policymakers work to resolve the dilemma, the short-term solution may simply be regarded as denial. Arguably presenting a case in point, General Lloyd Austin, the head of US Central Command in the Middle East was quoted by Reuters on Thursday as saying that Iran-backed Shiite militias have ceased to be a part of the on-the-ground conflict in Tikrit.

While this claim suggests that there is a diminished danger in giving support to the forces that are currently fighting there, the claim is also implausible on its face, as previous reports had indicated that such Shiite militias comprised as much as two-thirds of the fighting force that was challenging the Islamic State there. Indeed, numerous experts have indicated that Shiite militias are now more prominent in Iraq than the actual national army and that the latter is gradually being absorbed into a composite force led by Tehran and Qassem Suleimani, the commander of the Iranian Revolutionary Guard Corps’ Quds Force.