MANILA -- Political violence and terrorism have once more become a depressing routine in the southern Philippines. More than 80 people, many of them civilians, have been killed in bombings and indiscriminate fighting since early March.

The politically motivated bloodshed in Mindanao, the nation's second-biggest island, began in the early 1970s. Following decades of systematic relocation of mostly Christian settlers from the northern parts of the country to Mindanao, Muslims took up arms to fight for what they perceived as their historic homeland. Ever since, the demographic and political marginalization of the Moros, as the Philippine Muslims proudly call themselves, constitutes the root cause of hostilities in the south.

Ideologically, the call for a separate Muslim state in this predominantly Roman-Catholic country has been inspired by outside influences. In the 1950s and '60s, the government in Manila sent a large number of Moro students to Arabic universities in the Middle East. Instead of becoming supporters of the government, though, many of the Muslim academics upon their return to the Philippines turned into militant Islamic separatists.