1) No Pro-Israel regime will emerge from this conflict
The conflicts between Israel and Syria run deep at this point; both countries have significant and ongoing disagreements over their respective influence in Lebanon and the West Bank, Syria strongly objects to Israel’s continued occupation of the Golan Heights region. Those conflicts are not a result of the policy of Assad’s regime. It is true that not every potential Syrian regime would necessarily give financial and military aid to Hamas and Hezbollah for terrorist acts against Israel, as the Assad regime has done, or that every potential Syria regime would choose to ally with Iran–so in that sense, there is room for some improvement. On the other hand, Assad’s regime has resisted giving Hamas or Hezbollah chemical weapons or generally first-rate military technologies, which means there is also plenty of room for things to get worse from Israel’s perspective.
2) No Pro-American regime is likely to emerge from this conflict
Mostly because of America’s perceived (and real) ties to Israel. Again, there are plenty of reasons to believe that if the Assad regime fell, that the next regime might be better… but there are also reasons to fear that it might be worse, from a strictly American perspective. As far as what we want from Syria, we have similar interests to Israel: we’d like Syria to cut ties with Hamas, Hezbollah, and (especially) Iran. We’d also like to see Syria develop closer ties with Jordan and (especially) Turkey. And we’d like to see them stop meddling so much (or at least so explicitly) in Lebanese politics.
3) Keep an eye on those chemical weapons
Everyone assumes that Syria has chemical weapons, although it’s never been confirmed. But if they do, the Assad regime has kept tight control over them. However, should the Syrian government fall apart, suddenly control of those chemical weapons stockpiles become very important–the new regime, whoever that might be, will desperately want them, but so will lots of international groups. There will be some fear-mongering in the media about them, and who knows, we might even see a covert operation or two spill over into the front-page. But from the moment the Assad regime collapses, it could be awhile until it becomes clear that those weapons have not spilled out onto the international black market–this could make for a very harrowing time for counter-terrorism forces around the world.
4) At some point, as the Syrian crisis continues, Israel will likely consider invading Syria
There could be two reasons why. First, this kind of civil unrest and political instability tends to attract terrorists and violent extremists; anarchy means that no one cares if I’m plotting to blow up my neighbors. Israel has been known to invade their neighbors when this has happened in the past; most notably Lebanon, where they’ve done it a couple times now. And should terrorists start to use the chaos to Syria as a base of operations to launch attacks, Israel might decide to step in. The second reason Israel might invade gets back to those chemical weapons. If Israel fears that there is a realistic chance that those chemical weapons might end up in the hands of Hamas or Hezbollah, Israel could decide to take matters into their own hands by invading themselves preemptively–using basically the same rationale as we did in the Iraq War.
5) There isn’t much that the United States can do to pressure Syria
The United States doesn’t trade much with Syria, and Russia and China are intent on blocking any concerted global sanctions. Diplomatic pressure is going to be of limited use, when we’ve spent the last forty years trashing Syria and have basically no diplomatic relationships with them. We are extremely unlikely to invade Syria, and they know it. Just about the only other option left on the table is a bombing campaign like we used against the Qaddafi regime in Libya, and given the risks involved here even that is unlikely. Obama will feel pressured to do something, while the GOP will attack Obama for not doing enough, but at the end of the day there just aren’t many good options left on the table.
6) Any democracy that does arise in Syria will not likely last
Democracy may be the best form of government, but it is also hard–and Syria has none of the advantages you’d like to see in a newly formed democracy. In fact, Syria is so unstable right now that whatever government follows Assad’s regime will likely be short-lived, whether it is democratic or not. After all, my guess is that Assad hasn’t been a tyrant because he wanted to. My guess is that Assad has been a tyrant because he felt that was the only way to keep such a diverse country with so many conflicting political pressures from ripping itself apart. Syria may look small on a map, but it is an ethnically and religiously diverse country, at least one of whom desperately wants their own ethnic homeland (the Kurds), with a chunk of its territory occupied by a foreign power (Israel), a natural resource (oil) that’s easily stolen and sold on the black market by whoever controls the oil well, and in a region literally surrounded by private armies (AKA terrorist organizations) who would love to use Syria’s territory as their own personal base of operations. Yeah, I can’t see this going well.