In Spain having a seat in Congress or Senate means having part of the expenses of the campaign paid by the State. If you don't spend too much and get enough seats you get all your money back.
And reacting just like your attacker wants is stupid. If Israel did wanted to attack only Hamas this is not the right reaction. This only gives fuel to Hamas.
I'd go a step further: all is modeled after power. If you feel* you have more power it's because the other part is "less than you", not because you both have different strengths.
Read about EEE