The assassination of former Lebanese Prime Minister Rafiq Hariri on Feb. 14 has raised fears of a return to civil war in a troubled country and adds yet another wrinkle to the already complex equation in the Middle East. It is unclear who was responsible for the murder, but fingers are pointing at Syria. The government in Damascus denies any responsibility.

The killing underscores the fragility of peace in Lebanon and highlights Syria's critical role in maintaining stability there and throughout the region.

Mr. Hariri was a billionaire businessman who served as Lebanon's prime minister from 1992, with only a brief two-year period out of government. A devout Sunni Muslim who was nonetheless uneasy about the inroads religion made in Lebanese politics, Mr. Hariri was credited with overseeing the rebuilding of Beirut after a vicious 16-year civil war and with restoring stability to Lebanon. He stepped down as prime minister in October after breaking with Damascus over plans to extend the term of President Emile Lahoud, a pro-Syrian politician who had thwarted many of Mr. Hariri's economic reforms.