The Russian Defense Ministry announced that its warplanes have flown its first combat mission in Syria with American-led aircraft, . The Pentagon, however, has such a mission took place. U.S. Air Force Col. John Dorrian, a coalition spokesman, says the Russian announcement is “propaganda.” Needless to say, the situation is developing, and highly unusual.

The idea of the Russians and Americans working together on a joint mission in Syria seems odd for several reasons. Given that Russia and the United States since Moscow launched its first airstrikes there in September of 2015, it is difficult to see how Moscow and Washington could work together on shared targets.

During his first official White House press briefing today, spokesman Sean Spicer deferred questions to the Defense Department.

Even when former President Barack Obama wanted to work with the Russians on Syria, the Pentagon pushed back, . Pentagon officials believed that Moscow would not honor any agreements to coordinate on targets in Syria and that the Kremlin would use any intelligence it shared to bolster Syrian President Bashar al Assad’s regime.

Moreover, the Pentagon alleges that Russian planes have , not ISIS. Russia has also by the Pentagon that its aircraft are engaging in dangerous air maneuvers over shared Syrian skies that put American pilots at risk. Former Secretary of State John Kerry went as far as against Russia over allegations that it was bombing civilian targets.

None of this seems like a smooth segue into a joint air mission.

We can argue over if we think the Russians or the Americans are lying about the alleged joint mission, but, given how far apart the two nations are over how to best resolve the conflict, any aerial coalition would be strange at this point.

More on this as we get it.