Hamas initially served two purposes: firstly to continue an armed struggle against Israeli occupation and secondly to carry out humanitarian aid.
In the 1990’s Hamas took to suicide bombings to pervert the course of the Oslo accord. The Oslo talks were the first face to face efforts between Palestine and Israel to try to settle on some order out of the chaos. The Oslo accord was widely disliked by both Israeli and Palestinian groups, largely due to a huge and all-encompassing lack of trust on both sides. They’d been killing each other for decades after all. Hamas found that suicide bombs were a good way to veto decisions, and despite Israeli crack downs, Hamas still found support and strength.
Suicide bombing is patently unacceptable in the modern world, there’s no excusing any kind of murder. On the other hand, the reason why you never hear of Israeli suicide bombers, is because they have mass murdering fighter jets and a terrifyingly hi-tech, American funded military so there’s no need. They can slaughter safely from afar.
The Oslo accord put a newly formed group called the Palestinian Authority (PA) into power as an interim government of Gaza and the West Bank. After the second Intifada in 2000 Israel accused the PA of sponsoring attacks and clamped down on them. This enabled Hamas to gain more strength and support once again. Hamas set up clinics and schools and were, to many Palestinians, a breath of fresh air after the perceived corruption of the US backed PA.
In the first few years after the Second Intifada suicide bombings by Hamas were cheered by Palestinians who looked on them as retribution for the many people they had lost to Israeli rocket fire and air raids. Like I said in the intro, one man’s terrorist is another man’s freedom fighter.