Once you flood a country with small and medium arms, it destabilizes it for decades.
Ronald Reagan spread weapons all around northern Pakistan, and in my view began the destabilization of that country, which now has an endemic problem with armed tribes, militias and gangs. I saw the same thing happen in Lebanon shortly before, during the civil war that threw that country into long term fragility. More recently, we saw a civil war in Algeria (1991-2000) that left 150,000 people dead, which is really no different than what has been going on in Syria except that it was on a much larger scale and the West at that time decided to support the secular generals against the rebelling Muslim fundamentalists. The arming of Iraq post-Saddam has left it a horribly violent society for the foreseeable future (a plethora of US arms given to the new Iraqi military and police were often sold off to guerrillas). And while the war would have been longer in Libya if Qatar and France had not secretly armed the rebels, it likely would have had a similar outcome (what was really important was NATO attrition of Libyan armor). And in that case the problem the country now faces, of militia rule and fragmentation, would have been much less severe.
If people don’t think a flood of arms into the hands of Syrian fighters will spill over onto Turkey, Jordan, Iraq, Lebanon, and Israel/ Palestine, they are just fooling themselves. The Palestinians in the region have largely given up or been made to give up arms, in Jordan, Syria and Lebanon. But if small and medium arms become widespread and inexpensive, it will take us back to the late 1960s and early 1970s when Palestinian guerrillas shook Jordan, Lebanon and Israel. The Palestinians themselves always suffered from a resort to arms, and are best served by a peaceful movement of protest, and a remilitarization of their struggle would produce further tragic setbacks…
If you want practical action or even military intervention in Syria beyond financial and economic sanctions, there are only two ways to get it legitimately. That would be to find a way to pressure Russia and China to stop protecting Bashar al-Assad. The other possibility would be to find a way to abolish the one-country veto on the UNSC.
Dumping weapons onto the dissidents is really dumb, and so is invading Syria. Still, doing nothing while Assad murders anyone who disagrees with him is unconscionable. The only avenue we seem to have is to try and convince Russia and China to stop protecting Assad- the US would never in a million years give up it’s veto rights on the UNSC.