Over the past five years there has been a clear downward trend in the number of suicide attacks worldwide, with a particularly sharp drop in 2021. This trend is apparently the combined result of the significant weakening of the Islamic State following its military defeat in Syria and Iraq, and the withdrawal or considerable reduction of Western military forces in combat areas in the Middle East and southern Asia. In 2021 there were about 42 percent fewer suicide attacks than in the previous year, with a 48.5 percent reduction in the number of suicide attackers, and a decrease of 69 percent in the number of women participating in such attacks. A sharp drop of 44.5 percent was recorded in the number of attacks carried out by ISIS and its affiliates, and of about 35 percent in the number of attacks carried out by supporters of al-Qaeda. In general, there was a reduction of about 44 percent in the number of attacks linked to the Salafist-jihadi stream of Islam, although organizations linked to it continued to dominate as instigators of suicide attacks.