It doesn't matter what they say. It matters what's true, and it matters what's right.
It's as though you defend a child's tantrum because the child explained "my mummy didn't buy me any sweeties".
You think jihadis are in truth really pleased about how Palestinians were ethnically cleansed, how they can't get their homes back and how they're treated like dirt everyday?
That's retarded, they're mad as hell about it, and as it happens many non-terrorist Middle Easterners are mad as hell about it too. If you doubt that, read the 2004 Pentagon Defense Science Board Report.
Furthermore, many non-Middle Easterners are mad as hell about it too. Many jews are mad as hell about it as well, as you can see from looking up eg mondoweiss.net
Finally, many Americans - including veterans and ex-intelligence personnel - are mad as hell about the American money and lives being expended to harm the Middle East on Israel's behalf, which you can see by looking up eg The Council for the National Interest.
However, it does not mean that anger is justified, and it does not justify attacks on civilians.
Particularly drone "signature strikes" against first responders, which have killed MANY more people than 911.
Decide which standard you want to have, and then realize that it applies to your favoured side too.
Which by the way started most of the problems in the first place.
Don't try to justify Israel to me because you will look stupid when I list for you Israeli sources admitting Israel's aggression.
Starting with the Israeli national archives which have detailed the ethnic cleansing in 1948.
Stay on topic. Don't justify Israel. Just don't go there. Please.