After the collapse of Barak's government, Sharon was elected Prime Minister on 6 February 2001, defeating Barak 62 percent to 38 percent. Sharon's senior adviser was Raanan Gissin. In his first act as prime minister, Sharon invited the Labor Party to join in a coalition with Likud. After Israel was struck by a wave of suicide bombings in 2002, Sharon decided to launch Operation Defensive Shield and began the construction of a barrier around the West Bank. A survey conducted by Tel Aviv University's Jaffe Center in May 2004 found that 80% of Jewish Israelis believed that the Israel Defense Forces had succeeded in militarily countering the Al-Aqsa Intifada.