If you are ask by a LEO why you carry a knife never ever mention selfdefence. The term "brotzeit" would describe a reasonable and accepted cause.
I undestand that Israel is similiar. It's not a knife-carrying culture, and there are so many metal detectors and security checkpoints that hanging onto your knife may prove difficult. Like Germany, knives for snacks are acceptable, but self-defense is a no-no.
Mexico - Mexico has very strict weapons laws, and even the smallest pocket knife will get you into a boatload of trouble. It's justice system is "guilty until proven otherwise" and jails are notoriously bad (you may need to buy your meals if you want to eat). I cannot speak for knives as part of legal activities (i.e. fishing, cooking, tool kit, etc.), but EDC knives are strictly forbidden.