As always, a modicum of skepticism is warranted the "morning after," but the pledge to pull out the bulk of the Russian force seems genuine and, at this writing, the withdrawal is already under way. Putin's announcement appears to mark the beginning of the end of Russia's key but limited military intervention – the game-changer that started on Sept. 30, 2015, with Russian air strikes that enabled the Syrian army to regain lost ground, sever jihadist supply lines to Turkey, and drive rebels from hundreds of towns and cities.

Putin was clear in noting the Russian military presence that will remain in Syria, but was not so clear on its future use: "Our naval base in Tartus and airbase at Khmeimim will operate 'as usual'. They are to be safely protected from land, sea, and air."

This formulation presumably would allow for continued airstrikes on designated terrorist groups like the Islamic State and Al Qaeda's Nusra Front, including during the current "cessation of hostilities" negotiated by the U.S. and Russia. (Putin's phrasing may also be viewed as a warning against Turkey and/or Saudi Arabia not to act on recent threats to invade Syria.)