I made Aliyah back in 2008, and brought a Benchmade folder with me. I had no idea as to the legality of knives, or indeed possession/carry of any weapons in Israel, other than it might be "tough" to get a gun as a civillian.
So here's what I experienced during my most recent two year visit:
Shortly after making Aliyah, I had to go to the Ministry of the Interior to file some paperwork to begin receiving my "Kalanut" -- Aliyah funds. I had my Benchmade folder on me (with a partially serrated edge, I think the blade was 4in., but I don't still have the knife); simply in my pocket. As I approached the building I saw all the security and that made me think, so I pulled it out and asked my Israeli friend: "Hey... is this going to be a problem?"
He freaked...
But it wasn't!
He said: "You aren't supposed to have that in Israel." AND, turns out; he is technically correct, but I wasn't about to toss it in the garbage (my mom gave it to me), so I just walked right up to the security guard at the metal detector and handed her the knife. I apologized for having it, said I "didn't know it was illegal," and she laughed, smiled, and told me she'd give it back to me when I left... and she did, happily. No problems.
However, generally speaking, NO: As a private citizen, tourist, resident-alien, or regular local, you are NOT allowed to carry ANY knives on your person at all.
You will find, as with all things in Israel: There isn't really any uniform way in which laws, policies, or whatever, are enforced; and so in this case it REALLY is up to the cop you're dealing with... in fact it's always up to the cop you're dealing with. He might let you go, he might beat the hell out of you, and/or you might get to spend some time in one of Israel's scary-as-hell jails, or even worse: actual prison; so DO be very careful about dealing VERY nicely with ANY military, or local L.E.O.'s you might encounter whilst in posession of a knife. That is critical: Be polite, respectful, explain that you're "new to the country" and that you "didn't know," and apolgize. Try not to appear overly nervous or edgy, as Israeli security is heavily trained to detect that, and will respond with agression if they feel you're wilfully hiding something, or making any attempt at evading them in the course of their duly appointed duty for the public safety. And as always: Act very humbly. 95% of the time if you do this, the cop will simply let you go; and might even let you keep you knife, depending on the type.
Now, with that said: FIXED BLADE DAGGERS or DIRKS are NEVER a good idea to carry in Israel, not at all. They will attract attention 100% of the time and you will be questioned about it, and probably arrested or at least detained for a good, long while; and that's never any fun. Even if you're in the Army, you can't just go adding whatever you like to your uniform, especially at the lower ranks, so all you soon-to-be I.D.F. people: Don't think you can bring your "Scout Recon Tactical Fighter" and just clip it to your belt: If a M.P. sees you (and they will, at the bus stops or malls, etc); you WILL be written up (court martial) and you will be in semi-serious trouble.
Getting the knife IN the country, as has been said, isn't really hard. It's getting it back out without going to jail that's the problem, and yeah: The security at Ben Gurion is the tightest in the world: Don't bet on simply packing anything like a fixed blade in your checked luggage and getting on the plane. A small folder you *might* be able to explain away, but there's a 99% chance it will be found before you depart and you will be seriously questioned about it. My advice: Don't bring anything to Israel you aren't completely prepared to leave there.
Looking the part, again and as has been said, is important. If you look like a thug, and/or are found in a bad area with a reputation for crime, late at night and happen to be carrying a knife, you very well may be in serious trouble: It's all up to the cop.
If you are a nerdy American-Jewish kid (Star Wars Tee-Shirts help a lot), and you are obviously very nice and not intending to run around stabbing people, provided that you don't pull it out except to save your life or in some private area (like a Kibbutz or Moshav); you will be ok with most folders. However, AUTOMATICS of ANY KIND, GRAVITY KNIVES, Spring-blades, Ballisong, Switchblades, Air-gauge knives, Assisted-Openers, Shobi-Zue, Cane Swords, Ceramics, or any other kind of concealed/disguised blade, will land you in SERIOUS trouble. Regular, locking folders with a blade no longer than 4.5 inches should be ok, not strictly "legal", but ok. Additonally, it is absolutely forbidden to be found in posession of any of the following in Israel: Ballistic knives, nunchaku, metal knuckles, shuriken (throwing stars), as well as the non-toy replica versions of all these, including old military surplus items like decommissioned hand grenades, etc.
If it looks like an offensive weapon, and you bring it into public, and are not in fact a member of law enforcement or the Army, no matter if it's concealed or unconcealed; you are in fact guilty of a crime in Israel.
Generally speaking the cops in Tel-Aviv, Jerusalem, Haifa, etc, especially around the larger commerical centers, government buildings, and major places with lots of people like shopping malls and the cinema; are going to be less understanding about your knife than a rural, northern Israel cop would... but that's not "science", that's just my impression.
If you are busted in Israel with a knife, this is one time when speaking English, or flashing a California Driver's License, will help you out a lot! Don't attempt to speak Hebrew in that situation; use pefect English and give the officer your American, or foriegn ID as well as your local ID, and remain apologetc, sincere, compliant, and respectful. Remember: The Israeli Police aren't out there looking for YOU with your Benchmade; they have much bigger fish to fry, so don't agitate them and you'll do fine. They don't like busting Westerners over petty things, as they know this "turns people off", and they really aren't trying to do that; so "be cool" and you should be ok. Always remember to keep indentification on you at all times while in Israel, as that is in fact the law and is taken fairly seriously. And if you're found with no I.D. and a knife, well: That doesn't look very good, and you will go to jail while they figure out who you in fact are. You must be able to account for yourself, and unlike in the U.S.; you don't really have the "right to remain silent." You don't have a lot of rights in Israel, so try not to become self-righteous and combative with the local authorities because you are, afterall, in their country. Politeness is King, and always remember to smile warmly and make good eye contact!
And now for guns:
I think you can own a shotgun for hunting purposes, with a permit of course, and I think it's got to be kept at your local hunting club, in a locker. No rifles of any kind are allowed to be owned by private citizens AT ALL, the only exception being if you live in one of the more hostile settlement areas, in which case you can apply for a permit to own a rifle, or a handgun, or both. There are, of course, heavy restrictions on the types of guns you may own, and the ammunition you may use, how much of it you may stockpile, etc, etc, etc. It's not easy to get a permit either, and Bureaucracy in Israel can be a real pain in the bum; so be prepared for a long and stressful application process.
Back to knives for a second:
Remember this: There are metal detectors ALL OVER Israel, and security is everywhere. Chances are, if you walk around with a knife; it will be discovered during the course of daily events as it's very easy to forget you've got it on you, especially if it's small and you're from America where carrying a knife is no big deal... So then you decide to take the train up North one day, and wander into the station; only to set off all sorts of alarms, bells, whistles, and create a lot of very unhappy and nervous security guards in the process. That will not be a fun day for you.
If you really need a knife with you in Israel, then bring a small locking folder, Leatherman, or Swiss Army Knife with a blade no longer than 4.5 inches, and just be prepared to have it taken away from you by some cranky (or greedy) cop. Don't bring a $2,000.00 custom job, because if I were an Israeli cop I'd take that from you in a second.
I guess the overall message is: It's not legal, but that doesn't practically mean a whole lot in Israel, so just be smart about it and don't play games with Israeli security personnel.
--DarthZimmeris
*Professional Japanese Tamahagane Steel Chef's Knives are probably ok to own without permits, but NEVER to carry, and you are certainly going to pay a hefty "luxury item tax" on them upon import to the country.
**I have no idea as to the legality of stun guns or pepper spray in Israel, however I can safely assume that these are not legal to posess either, and will land you in serious trouble if found on your person in public.
***Remember: If you are caught in the commission of a crime whilst in Israel, the Israeli Police have the absolute right to detain you in a holding cell, without questioning or chance of release, for up to 14 days. They also have the right to search your entire person, car, home, place of work, etc, without a warrant. And this applies equally to "suspicion of criminal activity", meaning if the police receive an anonymous tip that you have committed, or are about to commit a crime; they are completely empowered to detain, search, question, and arrest you.