Berlin wall, what maybe 100 miles long and where the real threat was being shot on sight... wall construction wasn't the deterrence, but being dead, and even that didn't stop the attempts.
Israel isn't any better... wouldn't work here.
The Great Wall of China would be a better example of what would be needed, and that took nearly 1,800 years and some 25% of the country's' population to build. Not to mention it was more that 1,000 years ago that it was built.
Would be a Huge endeavor, one not likely to be done in modern times, except in someone's imagination!
Phil
