The Egyptian air force launched a wave of airstrikes aimed at members of Islamist opposition groups in the Sinai Peninsula Thursday, leaving at least 23 dead,

Egyptian army troops also conducted house-to-house raids in the Sinai town of Sheikh Zuweid, and regime pilots flying US-made Apache helicopter gunships continued to pound targets in the town as of Thursday evening. According to the Associated Press, residents of the town remained stranded without water and power as a result of the government onslaught.

The Egyptian government had already announced the imposition of new emergency laws this week in response to the assassination of Hisham Barakat, the government’s top prosecutor, killed by a remote controlled car bomb in Cairo on Monday.

The military assault in the Sinai came one day after the regime of General Abdel Fattah el-Sisi launched commando raids against the Muslim Brotherhood (MB) in Cairo, killing at least thirteen members of the Islamist party, which was declared illegal after being driven from power by the army during the July 2013 coup d’état, two years ago today.

Also on Wednesday, militants affiliated to the Islamic State of Iraq and Syria (ISIS) launched coordinated attacks against government checkpoints in the Sinai. The attacks led to the deaths of some 17 Egyptian soldiers and as many as 100 ISIS-linked militants. According to the Sisi dictatorship in Cairo, the Islamist fighters were armed with high-tech weaponry, including guided anti-tank and anti-aircraft missiles.

Israeli Prime Minister Benjamin Netanyahu expressed his solidarity with the Egyptian military junta in response to the fighting, warning that Israel would have to confront threats from Islamist forces based in the Sinai, Syria and elsewhere. The Israel Defense Forces (IDF) began massing troops on the Egyptian border in response to the attacks Wednesday.

The recent fighting represents a significant escalation of the ongoing conflict in the Sinai, which has not witnessed such intense fighting for decades, and a major step towards all-out civil war in Egypt. Egyptian media declared unequivocally that a “state of war” now exists in the Sinai Peninsula.

Thursday’s airstrikes continued the increasingly brutal crackdown waged by Cairo in recent months, which has included the destruction of entire residential neighborhoods in border areas.

“We will not stop until Sinai is purified from all terrorist dens,” the Egyptian military declared in an official statement this week.

The growing fighting between the Egyptian army and Islamist militants in the Sinai is in the final analysis the outcome of Cairo’s reactionary collaboration with US imperialism in the Middle East, particularly in the aftermath of the mass working class uprising in Egypt that toppled US-backed dictator Hosni Mubarak in 2011.

The military regime that emerged from Mubarak’s ouster initially organized elections that brought the MB’s Mohamed Mursi to power in 2012. The installation of an Islamist government within Egypt, supported by the army, was part of a broader policy of US imperialism of installing pro-US Islamist governments across the Middle East. The centerpiece of this strategy was the organizing of Islamist proxy forces in US-led wars for regime change in Libya and Syria, that were also supported by the Egyptian army.

In this strategy, the Sinai—a poor, largely desert area with Islamist influences and a limited Egyptian army presence under the terms of the 1978 Camp David accord with Israel—served as a transit point and base for weapons and Islamist fighters being funneled to Syria. These forces, boosted by recruits drawn from across Northern Africa, the Middle East, and Central Asia, have since continued to grow amid the continuing war in Syria and the growth of ISIS.

Cairo’s policy exploded, however, after Sisi responded to rising mass protests in the working class against the Mursi regime by launching a coup d’état and overthrowing the MB. Sisi’s goal, in which he had the full support of Washington and its imperialist allies in Europe, was to stifle mass protests in the working class by threatening to drown all political opposition in blood. The Sisi junta handed down more than 1,200 death sentences in mass show trials of Islamist figures between March and April of 2014 alone, as part of an escalating crackdown aimed at the MB.

Cairo’s agenda of domestic anti-Islamist repression conflicts with the continuing support offered by Washington for Islamist fighters across the Middle East. The Egyptian army is deeply dependent on US imperialism, which funds it to the tune of over one billion dollars each year, and continues to tacitly support Washington’s military interventions in the region.

At the same time, however, it finds itself compelled to mount ever bloodier crackdowns on the Sinai militants. Having initially assisted in their growth, the Egyptian military is now seeking to crush the Islamist factions on its territory, as well as using their presence as the pretext for cracking down on social opposition across Egypt.