But the blockade didn't really exist until a militarised fundamentalist group took over the Gaza strip, right? And the blockade has been eased during ceasefires? I might be wrong, but it looks like it is precisely the fighting that causes the blockade to continue and if the goal was to have the blockade removed, stopping attacks would be the most effective strategy.
I also think it is contentious to call indiscriminate attacks on a civilian population 'fighting' for anything. I do believe Palestinians have a right to fight against settlements but only in the figurative sense through civilised means. I believe the civilians in Gaza also have the right to fight against their Hamas leaders who are ensuring their suffering continues and worsens.
You want to play who started you're going to get to '67 and '48 real quick, and that's not only pointless, but doesn't really help Israel's case.
Both sides tend to pick a random point in time and pretend that's when it all started, nevermind what happened before, it was all peace and awesomeness.
And even if someone would try to play that game (which again, I think misses the real causes of the current round of escalated violence) it's very hard to argue that the Hamas leadership in Gaza started this.
It started either in the murdering of the 3 people in the west bank (might be done by Hamas, good chance that it was, we don't know, but there is zero evidence that it was something planned by the leadership in Gaza as an attempt to escalate the conflict) or by Israel's very harsh punitive response to it.
Also, let's not pretend that Israel would be cool with attack against military targets, when IDF soldiers die from Palestinian attacks Israel reacts more harshly than it does to your "normal" shelling of southern cities.
Put yourself in the Palestinian shoes for a second, what would you have them do?
Sit in quiet and do nothing?
They tried it for 20 years after 1967 (and about 20 years after 1948) and they got nothing.
Israel pushed them to a desperate, hopeless situation and they react in the only way they can, they quite literally has no other way.
Their rockets are not accurate or destructive enough to hurt military targets, if they shoot them from the open they'll all get killed immediately, what is your suggestion to them?
p.s.
When they tried to go to the UN or try to promote international boycott it was "diplomatic terrorism" and Israel reacted harshly (tightened the blockade, reduce the number of work permits in the west bank, expanded the settlements).
Don't get me wrong, I think boycott/international pressure would be more morally justifiable and effective, but they are unable to get any traction on that front.