As the US military strikes the Islamic State group in Iraq, Syrian President Bashar Assad's forces have significantly stepped up their own campaign against militant strongholds in Syria, carrying out dozens of airstrikes against the group's headquarters in the past two days.
While the government in Damascus has long turned a blind eye to the Islamic State's expansion in Syria in some cases even facilitating its offensive against mainstream rebels the group's rapid march on towns and villages in northern and eastern Syria is now threatening to overturn recent gains by government forces.
While Islamic State militants have so far concentrated their attacks against the Western-backed fighters seeking to topple Assad, they have in the past month carried out a major onslaught against Syrian army facilities in northeastern Syria, capturing and slaughtering hundreds of Syrian soldiers and pro-government militiamen in the process.
Yesterday, Islamic State fighters were closing in on the last government-held army base in the northeastern Raqqa province, the Tabqa air base, prompting at least 16 Syrian government airstrikes in the area in an attempt to halt their advance.
In the northern city of Aleppo, there is a sense of impending defeat among mainstream rebels as Islamic militants systematically routed them last week in towns and villages only a few kilometers (miles) north of the city.
An Islamic State takeover of rebel-held parts of Aleppo also would be disastrous for Syrian government troops who have been gaining ground in the city in past months.
"I think they (Syrian government) are finally realizing that their Machiavellian strategy of working with the Islamic State group against the moderates did not work so well, and so they have started to fight it," said Andrew Tabler, a senior fellow at the Washington Institute for Near East Policy.
But in hitting hard against the Islamic State group, Assad has another motive. His aerial bombardment of militant strongholds in Syria in a way mirrors that of the US military's airstrikes against extremists across the border in Iraq.
Analysts say Assad's strikes aim at sending a message that he is on the same side as the Americans, reinforcing the Syrian government's longstanding claim that it is a partner in the fight against terrorism and a counterbalance to extremists.
That comes after the US itself nearly bombed Syria after it blamed Assad's forces for a chemical weapons attack on rebel-held areas near Damascus last August.