We do not condone the usage of suicide attacks in any context.
The tactic of ‘suicide bombing’ was adopted by some Muslim militants quite recently (1980s), taken up by Hezbollah and then others. Suicide bombing is heavily contested in Muslim circles. Very few scholars seem to have explicitly endorsed its usage as legitimate Islamic practice – e.g. some scholars have given limited license for its usage in conflict zones as a last course of action – however this is not a consensus and particularly after 9/11 numerous scholars have been very critical of any form of suicide bombing. Among these one can count prominent Salafi scholars such as Shaykh ibn Uthaymin and Shaykh bin Baz before him, and Sufi scholars such as Shaykh bin Bayyah and Shaykh Afifi al-Akiti.
Commentators note that attacks involving a potential suicide dimension have been carried out throughout the ages by people from different religions and civilizations. Perhaps the oldest recorded story is of the Biblical Samson bringing the building down upon himself and his captors. Stories of the Knights Templars during the Crusades have also been recorded, and more recently the Kamikaze pilots of Japan reached notoriety.
A study by Robert Pape (University of Chicago) shows some interesting results. Pape has catalogued every act of suicide attack between 1980 and 2001. His results show that the largest number of attacks was conducted by the Tamil Tigers, a Marxist, atheist, revolutionary movement. This contradicts the popular assumption that suicide attacks are purely religiously motivated, and his study also shows that in every case a clear political objective lies behind the attacks.