Its two different desolation's, one is the 70 AD event, which is where I think Jesus would have saved Israel if they had of accepted Jesus but of course God knew they wouldn't accept Jesus at that time, so he postpones the 70th week and inserts the Church Age, Israel is seen as Dead Men's Bones for night 2000 years, then the HE {Anti-Christ} in verse 27 makes an Agreement {Covenant} with MANY meaning Israel and other Mediterranean Sea nations and reneges on those agreements. We can see in Daniel 11:40-43 who the MANY are besides Israel, they are all of North Africa, and countries he rolls through to get to Israel, Syria and Lebanon.Jesus cursed Israel and left them desolate, why wouldn't that be exactly who Daniel 9 is talking about? I mean think about, that's exactly what happened, they committed the greatest abomination that could ever be committed, they killed their Messiah. And the Messiah obliterated them for it in AD 70.
So the Anti-Christ desolates the Jews during the 70th week, but they were also left desolate in AD 70 in that God forsook them for 2000 some odd years up until 1948.