Hezbollah fighters stand guard as Hezbollah leader Sheikh Hassan Nasrallah, center, delivers a speech shown on a screen during a rally commemorating “Liberation Day,” which marks the withdrawal of the Israeli army from southern Lebanon in 2000, in the southern town of Nabatiyeh, Lebanon, Sunday, May 24, 2015. Nasrallah said Sunday that the region is facing “unprecedented danger” from extremist groups and vowed his militants will expand their involvement in Syria’s civil war in support of government forces. (AP Photo/Mohammed Zaatari)