More than 50 mid and high level State Department officials have signed a "dissent channel cable" urging the Obama administration to change its Syria policy and start taking military action against President Assad's forces in order to affect regime change.

A dissent channel cable is a confidential State Department forum for employees to express opposing views. While this is not unuisual, the number of officials and the strong criticism of White House policy is unprecedented.

Wall Street Journal:

The complaint filed by the State Department officials wasn’t unusual, current and former U.S. officials said, but the number of diplomats actively opposing a major White House position was.

“It’s embarrassing for the administration to have so many rank-and-file members break on Syria,” said a former State Department official who worked on Middle East policy.

These officials said dissent on Syria policy has been almost a constant since civil war broke out there in 2011. But much of the debate was contained to the top levels of the Obama administration. The recent letter marked a move by the heart of the bureaucracy, which is largely apolitical, to break from the White House.

The internal cable may be an attempt to shape the foreign policy outlook of the next administration, the official familiar with the document said. President Barack Obama has balked at taking military action against Mr. Assad, while Democratic presidential hopeful Hillary Clinton has promised a more hawkish stance toward the Syrian leader. Republican candidate Donald Trump has said he would hit Islamic State hard but has also said he would be prepared to work with Russia in Syria.

The cable warns that the U.S. is losing prospective allies among Syria’s majority Sunni population in its fight against the Sunni extremist group Islamic State while the regime “continues to bomb and starve” them. Mr. Assad and his inner circle are Alawite, a small Shiite-linked Muslim sect and a minority in Syria. In Syria’s multisided war, the regime, Islamic State and an array of opposition rebel groups are all battling each other.

“Failure to stem Assad’s flagrant abuses will only bolster the ideological appeal of groups such as Daesh, even as they endure tactical setbacks on the battlefield,” the cable reads, using an Arabic acronym for Islamic State.

Although Islamic State is losing ground to multiple, U.S.-backed offensives in Syria, Iraq and Libya, Western diplomats say they worry the group has embedded itself so deeply in the population that it will be a major influence for years to come, eventually going underground as its quasi-army is defeated.

One can understand the frustration of being forced to continue supporting a policy that has clearly failed. But how does overthrowing Assad bring us closer to defeating ISIS?

The many factions in the Syrian civil war fighting Assad will be even more difficult to unite to form a "transitional government" than the parties in Libya. And Libya is now a failed state with no government to speak of and ISIS running wild. Why would the diplomats expect anything differently in Syria?

US attacks on Assad would risk conflict with Russia. Would it be worth that risk to overtrhow Assad? Even if the US-backed and other "moderate" rebels would unite to join the fight, why would Russia stand idly by and allow their number one client in the region to fall? 

Iran is supplying most of the ground forces for Assad via Hezb'allah. Going to war with the Lebanese terrorist group would almost certainly mean attempts to carry out mass casualty terror attacks on US soil. 

These diplomats are privy to information not available to the public, so for them to call for such a radical change in policy could mean that the rebels are nearing the end of their ability to resist and desperately need air support. Russian bombing has been severe and, while killing a lot of civilians, also takes out rebel positions. As the rebels weaken, Assad's forces advance. This is especially true in Aleppo which is mostly held by the rebels but is being systematically razed to the ground by bombings and shellings. The fall of Aleppo would be a huge blow to the rebellion and American prestige. 

But Obama seems paralyzed and won't act. Feeble attempts to step up the bombing campaign against ISIS have had no impact on their strength.

A military victory by Assad over the rebels with Iran's and Russian support would only strengthen both in the region. But it would be a pyrrhic victory. Assad would rule over a pile of rubble that used to be a country. And with half the population displaced by the war, there won't be many people left to rebuild it.