Hi: well here is my story. I had purchased at a Seattle hardware store a folding knife with a 5cm blade. Typical pocket knife and short enought NOT to qualify as a weapon in Seattle.
Day three of my hike I was at a roadside 'saddling up' with two trails friends. In pulls a police car and they start chatting us up. Then one of the officers asks the simple question of "Does anyone have a knife?". I live a life without guile and said sure, I did. I handed the knife to the officer who opened it and passed it to the other officer. Then engaged in a long conversation that involved a cell phone call and a radio call. This took several minutes and the first officer asked why I was carrying a knife. I was a bit dumbfounded. I had had a knife with me on every hiking and hunting trip I was ever on. I said I carried it to cut string and apples plus pry out slivers, etc. Well they were having none of that. I was informed that if I wanted to carry a knife I could only carry a 'butter knife' and my little blade was hereby confiscated. I got a picture of my knife in evidence bag and a receipt. They drove off after reminding me that I could always come with them to the police station. I replied: "No sir!". They smiled and drove off.
Now, fast forward a week and I am having an evening coffee with a city police officer in Nazret. He about choked when I told him my story. He said there was no reason for anyone to take away a hiker's knife. Obviously, the other officers did not do well on their 'racial profiling' training. I mean a 54 year old American is a danger to the citizens of Israel with a pocket knife? I could do more damage with a rock.
Here is the kicker. I stopped in a Richochet [sp] sporting goods store in Be'er Sheva. Sure enough on display was a large selection of folding knives. Many of the knives were alot longer than mine!
My suggestion; don't take a large kife or a folding knife with an agressive look to it. Think 'Boy Scout' knives. I bet a clasp knife with a bottle opener would be fine.
As for self defense, see the 'rock' comment above.
Oh, my talk at the Seattle REI store on my INT hike is set for 26 Feb. at 1900. Please come! It was a great hike in a great land with great people!