What would it take for Israel still to control the Sinai Peninsular, and what would the impact be? Let's maybe say that Israel also controls the East Bank of the Suez Canal.
No such thing as Israel anymore? Good luck trying to keep the place. With the Egyptians starting wars every few years.
Well, the Israelis really gave it back as part of getting diplomatic detente with Egypt and because they had a serious scare during the Yom Kippur War. That happened in part because the Bar Lev Line, which was the static Israeli defense along the Suez Canal, broke at the beginning of the war due to an incredibly inventive Egyptian water crossing technique: they used high pressure water hoses to move the top sand out of the way and compact the stuff below it, making a series of ramps up the side of the Canal of the Israeli side. This allowed Egyptian light armour (PT-76s and things like that) to cross and establish a bridge head that engineer units could later follow.
These pumping systems were bought through various backchannel dealings, mostly by outright lying and saying they were for the Cairo Fire Department. West Germany provided two of the pumping systems in this way, without really understanding what they were for. In many ways, crossing the Suez Canal in 1973 was the greatest commando action of the war, and the Egyptians aren't given credit for it merely because they're Egyptian. Had they been Israeli it would be in all the history books.
But in any case, had their attempts to purchase these pumping systems been found out and stopped, then they'd have been forced to go with a normal amphibious operation against the Bar Lev Line, supported by commandos. This had been tried on a small scale in the War of Attrition and failed every time.
Long story short: The Egyptians fail the Suez Crossing at the beginning of the Yom Kippur War, then the Israelis keep Sinai. And if they're still there in 1973 without any large scale Egyptian resistance to stop them, then why
should they give it back?
Though this raises the question: what happens in 1982, then, when Israel invades Lebanon?
?What if the Jewish Authority had Bought the Sinai back in the 1930's, so it was part of Israel when Formed? [means No Gaza Strip]
- Why would they buy something so far from Jerusalem?
- How much $$ and power did the JA have back then?
They had a lot of power. Part of the reason they bought what they did was that they wanted adjacent land. They could've bought part of Suez, perhaps, but not all of it. It's like buying real estate: they only bought a block if they could buy every house. If one house on it wasn't for sale, then they decided to forego the whole thing.