 Complete the following phrase:  Closely allied with the Al-Mourabitoun, the PNONLA joined the Lebanese National Movement LNM in April 1975, playing a somewhat significant role in the controversial siege of the Christian coastal town of Damour alongside the Al-Mourabitoun, the PLO and Palestine Liberation Army units on 2022 January 1976, and later took part in the Spring offensive held in March that year on the Mount Lebanon region. Forced to go underground during the 