inb4 "TLDR" but I gotta spill some insight here as most of you'd expect.
That part of the world is such a shitshow. It's been 60+ years of just downright total war. (okay, fine... it's been like 3000 years...)
Here's the thing as I see it.
First of all, Hamas is not exactly a terrorist organization. They are a militant political power party. There are members of Hamas that might be especially militant, but I think the definition of 'terrorist organization' is more along the lines of al qaeda or small groups with intent to inflict terror and chaos to bring down the establishment. Hamas is probably more a step above that of the ETA in Spain, or the PIRA in Ireland, where they actually have political control, and ambitions beyond that of just killing their rivals. In fact, a group like al Qaeda's main goal is more along the lines of causing chaos and terror, in order to PROMOTE the ascension of a group like Hamas, or the Taliban to power.
Now, on that note, Hamas is actually a Taliban-like organization, where they have goals to implement sharia law and nationalism amongst their supporters (Taliban is Pashtun, whereas Hamas is Palestinian) Hamas is also intrinsically different than the Taliban in that they are fundamentally Sunni oriented, and the Taliban is a more broad islamist movement, and far more strict on the sharia law bullshit.
It's kinda funny how Hamas works though... they totally spit in the face of the PLO and Fatah support (Yasser Arafat was Fatah/PLO), even though both sides share just about exactly the same fucking goal - which is anti-zionist, bring back the pre-mandate Palestine, and oust this whole 'Israel' thing... Hamas seems more keen to politically and militarily crush their Fatah opponents in order to press their military measures, and As much as they do have ideas on economical issues and support funding social programs like schools and whatnot, they are far more knee-jerk when things go down that even remotely freak them out... Every 'truce' hamas extends to Israel, Israel immediately rejects it because it knows that that's just a bunch of bullshit, and Hamas is far from likely to live up to their word.
They are no terrorist organization, but they are a political party of mega bastard-machines hellbent on instilling their power and influence on the region... and they are by no means willing to sit down and have a chat with Israel like that of Arafat, who, though he was still a bit of a bastard when it came to influencing a 'gung-ho' attitude amongst palestinians, he at least got some productive things done that made SOME peace, whereas Hamas has done nothing but cause bullshit, because they are fully intent on war and use of military power. That's actually probably why Arafat lasted so long, was never arrested by Israel or assassinated, because Israel would much rather have a guy like him in power of Palestinian affairs rather that batshit militant fuckers like Hamas.
As for how good they are at military shit? Lets just say this much. Most of their rockets are either home made- unguided shit that makes the explosion montage in that "October Sky" movie look motherfucking productive. - or monkey copied iranian/soviet designs that are about 3 degrees of separation away from the soviet ones that actually worked - in the 50's or 60's.. Their guidance is hilarious, and the safest place to be during a rocket barrage from hamas? Right smack on the fucking target where they are aimed, because they land anywhere but.
for the hundreds of rockets shot off, only 27 have landed in urban israeli areas, and 60 or so have landed in densely populated areas of gaza itself and have caused far more palestinian casualties than Israeli. If I were a Hamas military commander, i'd call an immediate cease fire - in self-defense of my own land...
The Germans probably had better rocket command... in world war ONE...
As for Israel, sure there's the whole bullshit argument of "who took who's country and land" but ultimately, it comes down to the fact that both sides have their idiots, and they've both thrown enough stones at each other that nobody can point the finger anymore as to who's at fault. They're both at fault. They both suck, and the biggest part of that suck, is that they are a black hole vortex of bullshit for the rest of the world, and the biggest powder keg waiting to light ablaze since Franz Ferdinand...
and just for good measure, lets just do a quick introduction on what the fuck this "Gaza" place is..