It did not keep them safe from the invasion 2 years ago.

Those attacks were horrific, but certainly nothing that rises to the level of an "invasion".

They were invasion by definition: Palestinians crossed into Israel, invaded villages and towns. How come it's not an invasion?

Usually an invasion entails an intent to capture territory and occupy. A suicide terror attack is qualitatively different even if it’s large-scale. The boots on the ground could just as well have been rockets, whereas an invasion needs a longer term presence.

Palestinians crossed into israel from israel (occupied territories by israel). How can you invade yourself?

> occupied territories by Israel)

Gaza was not occupied. There was zero military presence in Gaza prior to October 7th.

Aim of an invasion is by definition to conquer.

I think the meaning of 'invasion' in the context of nuclear deterrence refers to an attempt to occupy.