May 15 1948 was before the war which Israel won capturing an extra 20% of land + Jaffa and West Jerusalem if you were Ben Gurion would you recognise any kind of final border after that? Go back to formerly recognising the border of 1947 would have meant giving it all up and that is why borders have never been formerly declared. I assume you believe that the borders of Israel are the 55% of Palestine minus Jaffa & Jerusalem as proposed by the UN in 1947 not the 78% Israel was left with when the war of independence ended in 1949 what today is called the Green Line and if a palestinan state were to be created you would say it should its borders should be the 1947 UN proposed border which would give them 45% plus Jaffa rather than just the remaining 22% that Israel captured from Jordan in 1967.
Gunmen in Egypt kill guard outside Niger embassy (Reuters)
from the article: Bulldozing Palestinian history on Israel's southern hills