The idea that Gaza is a threat to Israel is not true, Israel has a huge, sophisticated military. It is Israel which is the threat to its neighbors, it's launched many wars. Israel has preached the same kind of destruction about Gaza and actually carried it out.
Regarding the history of Israel and the Palestinians, You should look at the history of the occupation. In the Gaza Strip, the 5m high walls concrete walls between the few thousand settlers who use way more resources, occupied about 1/3rd of the land, while over a million people lived around them in poverty. It's very cruel and brutal apartheid/imperialism by Israel understandably made Gazans angry. Things like arbitrary detention, mass torture of Palestinians, assassinations and so on which are the underpinning of the military occupation, this is what pushes people to extremism.
Well the walls have been working fantastically well for Israel. Suicide bombings just don't really happen anymore. Yeah sure, the knifings have been going on, but those kill a lot less people.
15 years ago there used to be a bombing every week.
The suicide bombings only came after attacks by Israel, each one was a response for an attack by Israel, for example attacking apartment buildings with helicopter gunships. That's important to remember - they have a context.
Yes the wall is working well for Israel, it's annexed more of the West Bank by default, and is disrupting the lives of Palestinians massively, and also the migration of wildlife.
There's been quite a lot of violence lately, death toll is still pretty high since late 2015.
Regarding the history of Israel and the Palestinians, You should look at the history of the occupation. In the Gaza Strip, the 5m high walls concrete walls between the few thousand settlers who use way more resources, occupied about 1/3rd of the land, while over a million people lived around them in poverty. It's very cruel and brutal apartheid/imperialism by Israel understandably made Gazans angry. Things like arbitrary detention, mass torture of Palestinians, assassinations and so on which are the underpinning of the military occupation, this is what pushes people to extremism.