Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
What's the U.S. plan on Russia's "all out" invasion? Plus, a look at the strategy for fighting ISIS.
Syrian leader Bashar al-Assad will not survive the Syrian civil war, says Andrew Tabler, senior fellow at The Washington Institute. Asked on "The Lead with Jake Tapper" on Tuesday, "Do you think this ends with Bashir al-Assad alive?" Tabler replied, "No."
The brutal civil war in Syria claimed more than 6,000 lives in March alone, making it the deadliest month since the conflict began a little more than two years ago, the opposition Syrian Observatory for Human Rights reported Monday.
Some fear the death toll will become the new normal.
"Syria is literally melting down as a state and as a country," said Tabler. Tabler has briefed the Senate Foreign Relations Committee, and also authored "In the Lion's Den: An Eyewitness Account of Washington's Battle with Syria."
"Until now, the U.S. has stayed on the sidelines largely trying to shape the opposition, but it's increasingly difficult to look at Syria in the coming years as staying in one piece," said Tabler. As the human death toll and refugee flows go beyond estimates, "Washington is struggling to come up with a policy response that makes sense."
The Middle East is a vital geographic area for the United States, says Tabler.
"It affects everything, most of our major allies - Turkey, Israel, Iraq, and Jordan," said Tabler. "The spillover from the conflicts threatens those states, and threatens the regional security architecture as Syria descends into a failed state."
President Obama's red line on Syria has been a moving target. The administration warned Syria in August against the use or movement of chemical or biological weapons. In December, it became just the use, when Obama warned Syria in no uncertain terms in not to use chemical weapons.
"Now it is unclear exactly where that red line is, and what kind of substance it would be," said Tabler. Obama "does still have this red line. He calls it a game changer if chemical weapons are used, but it would depend on what chemical agent, and we still aren't clear on that from the White House."