Suicide bombing is a
paramilitary tactic which uses humans as an
explosive delivery system, employing a bomber to carry a concealed payload to selected targets, where they will detonate them in an attack which, if successful, is expected to kill the bomber as well as damage the target. These attacks are typically carried out on foot, with explosives concealed under clothing or in backpacks, bags, and the like. Vehicles can and have been used, however, enabling bombers to employ larger payloads and attack targets they would be unable to access on foot - suicide truck bombings were effectively used against the
American embassy and
Marine barracks in
Beirut in
1983, and a
2000 suicide bombing attack employing a small boat succeeded in crippling the American Arleigh Burke-class
guided missile destroyer USS Cole and killing 17 seamen onboard.
Though suicide bombing as a strategy has some precedent in the kamikaze tactics employed by the Japanese Empire in the Pacific Theater of World War II (and a closer resemblance can be found in the Japanese homeland defense operations planned but not implemented in the late period of the war), the idea of a sustained campaign of surprise attacks is traced to the separatist "Tamil Tigers" of northern Sri Lanka, who first began such a campaign in 1987. Immediately apparent precedents include the spat of bombings conducted during the Lebanese Civil War. Suicide bombing in turn influenced the IRA practice of "proxy bombing", which involved using a third party to deliver the bomb, usually coerced by operatives holding their family at gunpoint. Suicide bombing proved well-suited to militant separatist and resistance groups, especially those with a strong ethnic or ideological aspect to them, and they were adopted and employed by several such groups in the 1990s and the following milennial decade, most famously by Palestinian-aligned groups inside Israel and its occupied territories.
The primary strengths of suicide bombing are those of its relatively low cost and the difficulty of mounting effective defenses against it. A successful suicide bombing can cause significant loss of life and damage to property with a comparatively small, low-cost, and low-technology explosive device and a single operative who does not need to undergo significant military training. As scientific knowledge advances and the flow of information of persons across borders increases, bombmakers find it easier to learn their craft from printed and online sources, or by study with experts from sympathetic movements. Raw materials, in turn, are synthesizable given a moderately advanced understanding of chemistry or, barring that, simple to smuggle into conflict zones due to their small size and low cost, easier and more cost-efficient than bulkier, traditional armaments. These properties make suicide bombing a natural match for insurgent groups lacking the resources of larger, well-funded governmental forces and unable to conduct sustained, large-scale operations due to pressure from opposing intelligence and security forces.
The other strength of suicide bombing, that of the difficulty of defending against it, is based in large part on the high yield of modern explosives, which allows explosives capable of significant destruction to be effectively concealed. Bombers are difficult to stop because it is difficult to know that there is a need to stop them, and unlike a band of gunmen or other obviously malicious force, their nature as attackers is ideally not known until their attack has already been conducted. While a bomber's intent may be inferred from their unusual behavior or actions, even then they may be difficult to neutralize. Those defenses which can be employed against individual humans - usually, other humans acting through such structures as military and police organizations - typically operate on the assumptions that "enemies" will be at least in part motivated by concerns of self-preservation, can be deterred by the threat of after-the-fact apphrehension and/or retribution, and will not be capable of inflicting significant damage instantly before others have a chance to stop them, all assumptions which do not hold true for suicide bombing. The only way to defend a target against suicide bombing is to ensure no bombers get near it, and the only truly effective strategy of accomplishing this at the present time seems to be establishing some sort of perimeter around the target and individually inspecting those who wish to cross, which inspires annoyance or resentment in those searched, necessitates some form of security to protect the searchers and stop those who do have bombs, and is too expensive to employ at all potential targets. Resonance imaging, chemical sampling, and other advanced methods may enjoy some success in detecting the presence of explosives without need for individual searches, but are even more expensive, suceptible to failure or countermeasures, and does nothing to alleviate the need for force to back searchers up.
Of course, suicide bombing is no silver bullet, and suffers from distinct limitations and weaknesses. For one, while high yields enable suicide bombers to employ significant force, the constraints of available materials and the necessity of concealability still constrain them to blasts less strong and less focused than can be achieved with traditional military weaponry, and they often cannot inflict significant damage on armored or significantly "hardened" targets. This difficulty may recede as explosive, and particularly nuclear weapons technology becomes more advanced and more widely known, creating high enough yields to render mass constraints irrelevant, but until then the only practical way this limitation can be overcome is by the brute force approach of adding more explosive mass, usually concealed within automobiles. This addresses the situation somewhat, increasing mass and by granting some protection to the bomber, decreasing the need for total subterfuge, but the use of vehicles places limits on where bombers can go, and specifically where they can go without appearing out of place. This need to blend in applies on foot as well, limiting bombers to targets open to individuals (civilians, typically, unless they employ disguises and false identification).
These two weaknesses combined typically limit suicide bombers to so-called "soft" targets, usually lightly defended civilian targets like commercial or recreational destinations or crowded streets. Bombers can still inflict significant damage in this way, augmenting their explosives with improvised antipersonnel shrapnel deadly to unarmored targets, but this restriction to soft targets generally prevents suicide bombers from directly attacking their "real", military opponents. Thus they are forced to take the conflict to a political level, attempting to raise the cost to the opposition's supporters of continuing the conflict and tip the political calculus towards an acceptance of some or all of their demands. This indirect conflict can yield results - such "terrorism" proved instrumental to winning Algeria's independence from France - but results may vary with the specific political, military, and ideological context, and such an approach may further unify and radicalize opponents against groups using such tactics.
The other immediately obvious weakness of suicide bombing as a tactic is that it requires bombers to destroy themselves. Now, warriors have proven willing to take on suicide missions throughout history, but this is often in the context of situational necessity, with individual fighters who did not enter a conflict with the certainty of death "rising to the situation". Recruiting an operative with the explicit understanding that they will die is a more difficult matter, and while bombers may not require much in the way of tactical training, planners of suicide bombing campaigns often must dedicate significant attention to psychological training and preparation, shaping a bomber ready and willing to die for the cause who will not hesitate or abandon their mission. This may prove less of a problem in societies with strong warrior values, where death in service is considered rightful and glorious; small, tightly-knit, inwardly-focused cultures where a bomber may expect to be posthumously recognized and glorified by those he knew in life and serve as a heroic example and personal inspiration to others; cultures with a strong belief in reincarnation or a pleasant afterlife, in which death lacks a sense of finality or might be seen as a positive change; and times and places of significant suffering or hardship, where the percieved value of continued life is lowered and the importance of affecting change heightened. The confluence of several of these factors helps account for suicide bombing's concentration in identity-based resistance movements, and can partially explain the tendency of the influence of religious factions within these movements to increase following the adoption of suicide bombing tactics.
A less intuitive problem with this certainty of death is the fact that, as they will undergo only one mission, an organization pursuing a bombing-focused strategy does not generate leaders from within its ranks who are able to learn from experience, refine their tactics, and go on to lead forces of their own. This tends to concentrate experience and knowledge in the few who plan and direct but do not themselves participate in attacks, creating a less resilient infrastructure that may be significantly weakened if these leaders are captured or killed. This failure to establish heirarchical institutions may also weaken a movement which succeeds in forcing its demands and finds itself in a position to act in a governmental capacity, depriving it of the mid-level officers and bonds of allegiance necessary to efficiently run a state under such conditions.
It is worth noting at this point that many in the western world throughout the decades in which suicide bombing first rose to prominence find the tactic particularly distasteful, immoral, or worthy of condemnation. Some of this has to do with a near-universal tendency to oppose the intentional taking of one's own life which is, after all, a fairly strong meme, useful for maintaining a self-sustaining society. This falls short of a complete explanation, however, as the cultures in question have generally tended to accept the necessity of death, and even "suicide missions" in the context of armed conflict - Tennyson's celebrated Charge of the Light Brigade was a glorification, not a condemnation of such practices, and the idea of sacrificing the self for the greater good is also a strong meme, for good reason. Suicide bombings are strongly condemned even where equivalent "traditional" attacks, conducted with similar results and an identical realistic hope of survival, are met with less vituperation and even tones of grudging respect for the "enemy".
Part of this surely has to do with the tendency towards soft targets - though westerners have been forced, through the 20th century, to come to terms with the modern reality of total war and the effective demise of the combatant/noncombatant distinction, they were still able to view it in an abstracted, impersonal manner - bombing raids on major cities brought death in the form of metal machines thousands of meters in the air, and later the mushroom cloud was damn near a primal force of nature in the public consciousness. Suicide bombings are conducted by recognizable individuals, and make it clear that the death and destruction of war has a human origin and a human face. Another part of this, however, is surely the simple reason is that suicide bombing is a threat, a new way of warfare that promises to enable the formerly "weak" to leverage their advantages in the way that threatens the strong, something the strong will never countenance. The British, backed by the strongest surface navy in the world, reacted with horror and moral indignation to the temerity of the Germans to introduce submarine warfare in World War I. British "Redcoats", trained in the open warfare of the immediate pre-Napoleonic era, found the American revolutionaries' use of cover and hit-and-run tactics unfair if not unethical. Elite Japanese samurai saw the threat of ashigaru troops bearing firearms as an abominable inversion of the natural order (and they alone of this list had some success in postponing the inevitable, at least for a while). We are the strong, they are the weak, and how dare they forget it? Faced with a real threat to dominance, nations will dedicate all means at hand to prevent it, and while moral outrage may be the most visible, it is hardly the most effective. Perhaps the established powers will find a means to stay on top, perhaps it will be suicide bombing, or perhaps the next innovation added to the asymmetric warfare portfolio, that will upset the order of things once again. Perhaps something will come along to render the issue moot. For the immediate future, however, thoughtful observers should not expect it to go away.