Imagine a group of civilians calling themselves the Canadian Liberation Front. Imagine that they resented the actions of the US so much that they would kidnap two US soldiers. Would it then be reasonable for the US to engage in a full-scale invasion of Canada? Would it be reasonable for the US to bomb Canada's civilian infrastructure of commercial and industrial facilities? Would it be reasonable for the US to engage in bombing campaigns against Canadian bridges, and strafing runs by jet fighters against Canadian civilians?

No, of course not.

So why is it reasonable for Israel to do exactly the same thing against Lebanon and Gaza?