The United States is offering Russia a new military pact against the Islamic State and al-Qaida in Syria, according to a leaked U.S. proposal that, if finalized, could dramatically alter America’s role in the Arab country’s five-year civil war.

The document, published by The Washington Post, calls for joint bombing operations, a command-and-control headquarters and other synchronized efforts. U.S. and Russian officials with expertise in intelligence, targeting and air operations will “work together to defeat” the extremist groups, the eight-page paper states.

U.S. Secretary of State John Kerry, who was to discuss the proposal in Moscow Thursday, declined to comment.

“I’m going to Moscow, meeting with President (Vladimir) Putin tonight,” Kerry told reporters. “We’ll have plenty of time to talk about it and I’ll give you all a sense of where we are.”

Putin spokesman Dmitry Peskov said only that joint U.S.-Russian efforts were key to fighting terrorism in the region.

Such a partnership would undercut months of U.S. criticism of Russia’s military intervention in Syria. And it would put the U.S. alongside Syrian President Bashar Assad’s chief international backer, despite years of American demands for Assad to leave power.

Russia would be getting what it wanted since it first intervened in Syria on Assad’s behalf last September — to be a leader in an international alliance.

Washington has rebuffed Moscow’s requests for military cooperation, accusing the Russians of using anti-terrorism objectives as a pretext for protecting Assad’s position, of repeatedly violating truces and attacking moderate rebel groups backed by the U.S. or its allies as well as civilian targets.