What are the theological reasons some Protestants are Zionists? Zionism, founded by Theodor Herzl, is a movement for reestablishing a political nation for the Jewish people. Thus, what are the theological reasons why some Protestants are Zionists, especially in the U.S.?

(cf. this question)
It would be wrong to think that a majority of Protestants are Zionists, but Christian Zionism is nevertheless a substantial movement, especially in the United States. There is a belief among some Christians that the return of the Jews to the Holy Land, and the establishment of the State of Israel in 1948, is in accordance with Biblical prophecy. The idea that Christians should actively support a Jewish return to the Land of Israel, along with the parallel idea that the Jews ought to be encouraged to become Christians, as a means of fulfilling a Biblical prophecy has been common in Protestant circles since the Reformation.

Some Christian Zionists believe that the gathering of the Jews in Israel is a prerequisite for the Second Coming of Jesus. This belief is primarily, although not exclusively, associated with Dispensationalism, a movement begun by John Nelson Darby in the 1830s. For those who eagerly await the coming of Jesus, it is important to accomplish the return to Israel as quickly and as thoroughly as possible so that Jesus can return and establish his kingdom on earth.

Barbara R. Rossing says, in The Rapture Exposed, page 23, that Darby  invented 'dispensations' – intervals of time ordering God's grand timetable for world events. She says (pages 55-56) the dispensationalist's script ca1ls “these things” absolutely necessary for Jesus to come again to reign on earth:


The rebirth of the nation of Israel;
The Rapture of born-again Christians off the earth;
The emergence of an evil Antichrist (and his one-world currency),
probably from Europe;
The Antichrist signs a seven-year peace treaty with Israel, setting
in motion the seven years of tribulation – but the Antichrist will
break the treaty after three and one half years;
The rebuilding of the temple in Jerusalem and resumption of animal
sacrifices there;
The desecration of the temple by the evil Antichrist, followed by the
second half of the seven-year period of tribulation;
Jesus' return in the "Glorious Appearing" exactly seven years after
the Rapture, beginning with his touch-down on the Mount of Olives,
which will split the mountain into two.


One of the resolutions adopted during a series of Bible and Prophetic Conferences held across North America beginning in 1868 states:


  We believe that the world will not be converted during the present dispensation, but is fast ripening for judgment, while there will be fearful apostasy in the professing Christian body; and hence that the Lord Jesus will come in person to introduce the millennial age, when Israel shall be restored to their own land, and the earth shall be full of the knowledge of the Lord; and that this personal and premillennial advent is the blessed hope set before us in the Gospel for which we should be constantly looking.