Arab nationalism died decades ago. In my understanding, that was basically because of the movement's inability to effectively deal with Israel (ie their losses in the 56, 67 and 73 wars). Despite the nationalist rhetoric, Arab states were very divided during those years and Arabs came to view that division as the key reason for their failure to defeat Israel. Arab nationalism came to be associated with division among the Arabs. Its failure gave rise to Islamic fundamentalism, which Arabs came to believe would unify them and help them avoid the disasters of the past. Of course, Arab nationalism is many times more preferable than Islamic fundamentalism, but how to get Arabs to change their minds? Look at the success of Hamas and Hezbollah. They've stood up to Israel in a way that no Arab secular movement has yet managed to.
i know, thats what 60 years of unconditional US support for heavy-handed Israel and Middle-East oil-driven interventionism has led to... the radicalisation of the Middle-East, and the recent victories of the Islamists... never too late to change course, the nationalists are not dead, but they've learnt not to trust the US any more... and they are not going to fight a lost war against both the Islamists AND the US... perhaps one thing for the West to consider is they don't have "destruction of Israel" on their charter...
if he had, hamas / the islamists wouldn't be in charge right now... but the point isn't about israel, its about who do you want to deal with ultimately, religious fanatics, or secular progress-minded guys?...