It isn't often that I hear a new idea, but this one, from commenter Andrew, has some real brilliance behind it:
All Israel needs to do is pick some date with some historical relevance to the time of the Roman occupation, then make a festival (just celebrate an unsuccessful rebellion of the Jews against Roman rule or something), celebrate the great influence Jews and Romans had on history (this will remove an anti-Italian slant from the festival and allow Christians to celebrate with us), and prepare speeches and texts in both Hebrew and Latin.
In the texts refer to Romans and Jews very very often and use the Latin word "Palestina", the Roman name for the protectorate/province in place of Hebrew "Yisrael".
In fact we can use this method a few more times to reach other goals.
Celebrate the Muslim invasion because it allowed the Jews to return to Jerusalem. Invite the Hashemite king to the celebration.
Celebrate the Persian invasion and the Great King.
If our enemies use made-up history against us, just celebrate real history choosing occasions where we celebrate our enemies' ancestors and their stay in our land.
It will be difficult for the Arabs to condemn us for celebrating the Muslim invasion. And as long as we celebrate the invasion they cannot pretend that it wasn't an invasion and say that Jerusalem is Arab, not Jewish.
It will be difficult for the Iranian regime to erase Israel from the map, if Israel celebrates Iranian rulers of the past. They would have to erase those rulers from history as well and lose their past as they want us to lose ours.
And it will be difficult to pretend that "Palestine" was an Arab state that existed before Israel was "founded", if we celebrate the fact that our country was once the Roman province of "Palestina".
So, are we going to start a new holiday at the end of April to celebrate the Muslim conquest of Jerusalem in 637 - which did indeed allow Jews to return to their capital after the Byzantines defeated them a decade earlier? (If anyone can find the actual date, Gregorian or Muslim, I'd appreciate it.)