"God's permission" is presumably whatever David Barton happens to think at the time. One could hardly think of anything more blasphemous to a religious believer. But there again, most understand that the State of Israel is not the same thing as the Kingdom of Israel in the Bible. And there is nowhere in the Bible where the current borders are mentioned. Besides, #1687770 is right that the US has maintained the same position on borders, that is the 1967 ceasefire line, through many Republican and Democratic administrations, including this one.
@ niv
I agree, but only for the period after 1955. Beforehand, France and, during the War of Independence, the Soviet Union were more supportive.
@ Citizen Justin
The borders of Eretz Israel - the land, not the state, of the Jews - covers the land allotted to the Twelve Tribes. This goes roughly from Mount Hor (probably in what is now Lebanon) down to south of Gaza, but not including the Negev desert (now in Israel) or the Sinai peninsula. East to West, it ran from the Mediterranean coast to the Jordan river. Initially, the tribes of Gad, Manasseh and Reuben were allotted land to the east of the Jordan, but that disappears in later books of the Bible.
The additional land as far as the Euphrates to which you were referring has usually been interpreted to be the land that would be occupied by Eretz Israel when the Messiah comes.
Eretz Israel should be not be confused with the Kingdom of Israel in the Bible which ran from the Bekaa Valley (now in Lebanon) as south as what is now Tel-Aviv (but not as far south as Jerusalem) and from the coast as what is now Amman, Jordan.
Hope that helps.