Killing by suicide has a history, in Shi'a Islam, that has passed into legend. The legend has real roots in history:
Even the most powerful and carefully guarded rulers of the age—the Abbasid and Fatimid caliphs, the sultans and viziers of the Great Seljuk and Ayyubid empires, the princes of the Crusader states, and emirs who ruled important cities like Damascus, Homs, and Mosul—lived in dread of the chameleonlike Assassin agents. Known as a fida'i (one who risks his life voluntarily, from the Arabic word for "sacrifice"; the plural in Arabic is fidaiyn, or the present-day fedayeen), such an agent might spend months or even years stalking and infiltrating an enemy of his faith before plunging a dagger into the victim's chest, often in a very public place. Perhaps most terrifying, the Assassins chose not only a close and personal manner of killing but performed it implacably, refusing to flee afterward and appearing to welcome their own swift death.This is the interesting part of the article, though:
They developed a means of attack that negated most of their enemies' advantages while requiring the Assassins to hazard only a small number of their own fighters. As with any effective form of deterrence, the Assassins' targeted killings of hostile political, military, and religious leaders eventually produced a stable and lasting balance of power between them and their enemies, reducing the level of conflict and loss of life on both sides.The article clearly wants to bring the Medieval facts forward, as an analogy to our present time. Now, for our modern conflict, "targeted killing" is what we usually use to describe our drone strikes in Pakistan and elsewhere. This is likewise aimed at "hostile political, military and religious leaders," as among the Taliban.
Is it an effective form of deterrence? Will it inexorably produce a "stable and lasting balance of power"? That seems far more questionable.
Yet assume for a moment that it was the case. Would this not make assassination a moral weapon of war? After all, it kills few (and fairly precisely), risks few lives on your own side, and is (we are assuming) an effective deterrent that leads to stability and relative peace.
The argument against assassination, at least in democracies, is that a core function of the democracy is to provide the citizens with the leadership they choose. Killing their elected leader is, in effect, to deny their sovereign status; it is a more serious offense against them than to kill a soldier (the theory goes), because it strikes at the root of what makes the state legitimate and valid.
The counterargument to that is to point out that it is only natural that the elected politicians who write the laws should view the assassination of elected politicians with a special horror. Yet I can't think of a single elected politician whose life I would trade for most any soldier I have had the honor of knowing. It is the function of the soldier, of course, to hazard his life for the politician. That fact, however, means that the sort of people who choose soldiering are on average better people than the sort who choose to pursue political power, with all that entails.
The Assassins were better enemies than our current foes, who seek to wage war not on politicians but on people. Suicide bombs in a marketplace are no moral weapon at all; they target neither soldiers nor politicians, but innocents. In part this is because our enemies are weaker than the Assassins ever were. If they had the strength to strike at our elected officials, they would do so; terrorism is the best they can manage.
Does that suggest that we should wish for stronger enemies? We're likely to get them, thanks to current policy.