A delusion is a fixed, false belief in something that is not real or does not exist, and is held despite evidence to the contrary.
This is what delusional people look like:
Rabbi Abba Hillel Silver, 8 May 1947 UN — That the return of the Jews to Palestine would prove a blessing not only to themselves but also to their Arab neighbours
Ben Guron — It is because we are the children of the Jewish people and it is the only homeland of the Jewish people that we have rights in this country. We are returning to Palestine
Rabbi Fishman at the UN Special Committee on Palestine — Throughout their exile, Jews have steeped themselves in memories of their homeland.
Herzl: — The agreement could take the following form: His Majesty issua a most gracious invitation to the Jews to return to the land of their fathers; this invitation will have the force of law and will be made known to the Powers in advance.