Over the past several days northern Syria has witnessed some severe blows to rebel groups that were supported by the United States.Among them, a group called the Steadfast in this group, another, the Syrian Revolutionary Front.These were groups in whom the U.S. and other Western nations placed great hopes of being able to oppose both the Assad regime and also the radical group ISIS, or the Islamic State.Liz Sly of The Washington Post reports on what happened in the north of Syria yesterday and the days just before that.What's gone on there?Well, basically we saw this assault by the Jabhat al-Nusra front which is linked to al-Qaida,first against one rebel group called the Syrian Revolutionary Frontand then after that, they seemed to sweep through other bases in other areasand basically all of the moderate rebels in northern Syria are now on the run.The Harakat Hazm, or the Steadfastness group ― that's a force that I had read described by at least one expert at a Washington think tank as well-organized militarily, secular in orientation.Was this a great blow to them, what happened yesterday?Yes, this was a huge blow to them.They had been the first recipients of U.S. anti-tank missiles.They were supposed to prove that Syrian rebels could be trusted with American weaponsand they had received other kinds of aid in the form of non-lethal aid, such as vehicles, food ―they were hoping that they would become the vanguard of a moderate rebel forcethat could take on both the Islamic State and the regimeand now they've just been ejected and scattered from their base and much of that gear has ended up with Nusra.