In 2015 over 99 percent of suicide attacks were committed by Moslems, most of them Sunni Moslems influenced by a form of Islam (Wahhabism) heavily promoted by Saudi Arabia for decades. While there were fewer suicide attacks in 2015 than in 2014 the number of people killed (about 4,400) was about the same as 2014. Suicidal attacks (usually with explosives) have become very popular with Moslem religious fanatics because doing it requires lots of enthusiasm and very little skill.
Suicide attacks are nothing new and have been used for thousands of years. But heavy of use of this tactic comes and goes like any other trend. The current revival began in the 1980s, largely in Lebanon and Sri Lanka. Between then and 2001 there were nearly 400 suicide attacks in 14 countries. Seventeen organizations planned and carried out these attacks. Seven of these organizations were destroyed or stopped using suicide attacks by 2001.
The first attacks were made in 1983 in Lebanon, organized by the Iran sponsored Hezbollah (a Shia Islamic terror group). In Sri Lanka, the Tamil Tigers (or LTTE) carried out their first suicide attack in 1987. By the time the Lebanese civil war ended in 1990 at least 50 suicide attacks were made there. Through the 1990s, the Tamil Tigers were the most frequent user of suicide attacks. Attacks also began to show up in Central America, Africa and the Balkans, all committed by Iranian backed Shia terrorist groups. In 2000, Palestinian organizations (influenced by the success of Hezbollah) began to use suicide attacks more frequently, staging at least 21 attacks through the end of 2001. Early in 2002 the number of Palestinian suicide attacks increased until Israel developed new counter-terror tactics and went after Islamic terror leaders, specialists (bomb builders) and terrorist bases in the West Bank. After that the number of suicide attacks declined and by 2005 Israel has virtually eliminated Palestinian terror attacks inside Israel.
In both Lebanon and to a lesser extent in Sri Lanka, the terrorist organizations took advantage of religious beliefs that honored extreme sacrifice. Added to this was exploitation of economic and political grievances, thus making the suicide attackers into heroic characters. In addition, families of the suicide volunteers received generous (by local standards) economic rewards. Until in 2003 families of Palestinian suicide bombers receive up to $33,000 (from various sources, mainly Iraq and Saudi Arabia). Financial incentives like this have become common and the Palestinian government now pays them out of foreign aid cash.
Willingness to make a Faustian bargain is an ancient human trait and the terror organizations exploit it to recruit their bombers. Even without recruitment, it is not uncommon for young men to commit horrible crimes, "to become famous." What began as a Shia influenced tactic, suicide attacks have been adopted by Sunni (mainstream) Islamic groups and now Sunnis carry out over 80 percent of the attacks. Even after September 11, 2001 most senior Sunni clerics have gone along with this, although there was growing resistance to the religious acceptability of suicide attacks by Islamic scholars. By 2015 many, if not a majority, of senior Islamic scholars opposed (to one degree or another) the use of suicide attacks.
Historically, such destructive terror tactics last about a generation, then fall out of favor. This process is speeded up by the fact that most governments condemn the practice. Distaste for suicide attacks will grow, in the current situation, as more teenagers are recruited for the duty. The younger kids are, as with most trends, eager to outdo their elders. But suicide attacks are a tactic of despair, the last grasp tactic of a spent force facing inevitable defeat.
When the September 11, 2001 attacks occurred there were at least a dozen terrorist groups using suicide attacks (some more than others); the Islam Resistance Movement (Hamas) and the Palestinian Islamic Jihad of the Israeli occupied territories; Hezbollah of Lebanon; the Egyptian Islamic Jihad (EIJ) and Gamaya Islamiya of Egypt; the Armed Islamic Group (GIA) of Algeria; Barbar Khalsa International (BKI) of India; several Kashmiri separatist groups in Pakistan and India, the Liberation Tigers of Tamil Eelam (LTTE) of Sri Lanka; the Kurdistan Worker's Party (PKK) of Turkey; and Al Qaeda (which carried out the September 11, 2001 attacks). Now there are many more Islamic terror groups using suicide attacks, in large part because it is a lot easier now, because of the Internet, to publicize and glorify the suicide bombers and reach like-minded men (and a few women) to try it, if only once.