For years the military has said that Saddam had WMDs, but they were not the "sexy" variety of Biological or Radiological (if you discount Anthrax and the most basic dirty bomb tech). That's right Chemical weapons. Chlorine is easy to produce, but Blister agents like Mustard gas, or Nerve agents like Sarin are not. He had tons of the stuff, and what's more he used them against the Kurds. So we know it was there. But the stockpiles that we had expected to find had disappeared.
You may not know it, but al Qaeda actually had brief flirtations with chemical warfare in Iraq. The very real danger of a few loose chemical rounds that might have been picked up and lobbed in on the insurgent's daily shoot 'n scoot, had the Brass at the time freaking out. I was given some truly terrifying set of orders, and with the strong realization that we simply did not have the equipment to decon the FOB, realized that if there were chemical weapons lobbed at us, I was probably going to die horribly. Thankfully that never happened. But where did all those weapons go?
Most went to . . . Syria. They went through the same "pipeline" that al Qaeda in Iraq funneled insurgents back into Iraq. You see the problem now? See one of the things Saddam was always sure to do, was hide the evidence. It didn't matter that his regime was sure to fall, when it looked like the US was actually going to go through with it he was sure to send as much of anything that could give the US validation, as far away from Iraq as possible. Politically speaking I think he was hoping that international pressure would force America to end the war and still leave him in power, though I am not certain what he had in mind.
So now the Assad regime is close to falling. He really doesn't have anywhere to go, and with the Death of Qaddafi, and Saddam, he is probably certain that he would not make it out alive. This is of course assuming his own government wouldn't kill him for trying to desert. Dictatorships do not usually end well. So what to do? Well all those weapons are just sitting there. It's a scary thought.
Will Assad actually use them? Well look at it this way, his troops are losing. Slowly but surely he's losing. He can't retreat, he really doesn't have anywhere to go. He has used the superior tech at his disposal, and he's losing. He's laid landmines. He's bombed whole villages out of existence (people and all) and that's still not stopping the tide against him. The international community really consists of a few blocs, the Russians, the EU, the Americans, The Chinese, and regionally Israel, several Arab states, and Iran. Now of all of those Blocs who will object to the actual use of Chemical Weapons. The US, EU, and Israel. The problem; Both the US and EU are in the middle of serious financial turmoil and may not be abble to afford action, and Israel. . . well you saw how well it went for them when they got involved in Lebanon. So he may be taking a not unreasonable calculation that he can use them and get away with it.
So in short, yes I think Assad will use them. I think President Obama is bluffing. It would take a hell of a lot more than 75,000 troops to secure Syria, and it would mean yet another round of nation building, something he has actively campaigned against. His emphasis on counter terrorism (filling body bags with pieces left over by drone strikes) over Counter Insurgency (boots on the ground, winning hearts and minds through civil works and such) means that he will be loathe to get involved in a fight that could very well turn into another Iraq if not done properly.
The solution? Sorry I don't have one here. There are no good solutions. The best possible outcome is that the rebels just back off and starve Assad out. I do not thing that they have the stomach for that kind of fight, nor do I think they have the tactical imagination or proficiency to carry out a campaign like that. If this goes on much longer its entirely possible that it will spill over into other countries, and you have to wonder where it will end.
The Middle East has never really been stable. I suppose that's what you get when you build a house on sand. No matter how this plays out you can bet that it will leave a lot of deep, long lasting scars in the region. We will have to be ready to pick up the pieces. React Adapt and Overcome.