To fight all forms of Nationalism is the blessing of being a Marxist. Whether Lebanese, Palestinian, Syrian, Magna Syrian, Arab, Phoenician, and Zionist is the blessing to have the eyes of an Internationalist that sees people are people whereber you. By far, the most catastrophic form of Nationalism is that of the Zionists, for they expelled Palestinians from their homes, established a racist state, and still deny the existence of others. In fact, Zionism is an exclusive form of nationalistic colonialism. They destroyed and demolished cities far worse than the Serbs did in previous Yugoslavia.
Other forms of nationalism vary between one type of followers or another. Some attain the attributes of Zionism in terms of exclusivenes.
For me, seeing from the eye of an Internationalist Marxist, all forms of nationalism are reactionary, and play the role to seperate the Proletariat.
PS: Wanted to add that we even got Beirut Nationalism