3-4 decades means 30-40 years. (ie: 1967) As far as 1948. Ben Gurion ordered Plan Dalet before 1948 to wipe out the Palestinians and villages beyond the UN proposed lines. Don't be Naive and read history. Israel is still taking land. Have you ever heard of the West Bank? Think.
Report: IDF find M-16 rifle hidden in Palestinian's car in West Bank (Haaretz)
from the article: Peres to Haaretz: Israel could reach a peace deal with Abbas