Rob, that is an interesting point that I was not aware of. I am interested in quotes highlighting the difference if anyone has time to find them.
I am struggling to find any sensible justification by the Watchtower to show the prophecy should have two fulfillments. The reasoning is either circular, or "it must have two meanings because we want it to". Here is the main article I can find.
***gochap.5pp.83-89pars.29-41ForetellingtheTimeforWorldRulership***
Is that, however, all there is to the matter? There is no basis for doubt that Nebuchadnezzar’s dream of the heaven-high tree was prophetic, it being inspired by Jehovah God. But is the dream’s fulfillment limited to that ancient fulfillment on the person of one man, King Nebuchadnezzar, for him to learn a lesson regarding rulership? Is it through his personal experience that the purport of Jehovah’s dealing with him is achieved, namely, “that people living may know that the Most High is Ruler in the kingdom of mankind and that to the one whom he wants to, he gives it and he sets up over it even the lowliest one of mankind”? (Daniel 4:17) By setting up over the kingdom of mankind “even the lowliest one of mankind” does the Most High God set up over mankind the lowest grade of rulership over mankind? Evidently not! (Daniel 4:36, 37) For the “people living” in our momentous twentieth century, Nebuchadnezzar’s dream must have a further and more far-reaching fulfillment. It does!
30 Ancient facts certify the first fulfillment of the dream of the king of Babylon. How do the later facts establish the larger and complete fulfillment of that same dream? Well, Nebuchadnezzar, who for the time being back there was pictured by the massive tree, was ruler of the Babylonian Empire. So he symbolized rulership on a world scale, having worldwide recognition. Likewise, the “tree” that was illustrated by him stood for rulership on a scale grander than that held by the king of Babylon. At that time, what rulership or dominion was greater than that of Emperor Nebuchadnezzar, which stood without a rival on earth? Only the rulership of the one whom Nebuchadnezzar acknowledged to be “the Most High,” “the King of the heavens.” (Daniel 4:34, 37) For that reason, the heaven-high, life-sustaining tree of the dream symbolized the UNIVERSAL SOVEREIGNTY of the Most High, Jehovah God, particularly in its relationship with our earth. This Universal Sovereignty is eternal, “to time indefinite,” for all generations.
31 Such a meaning attached to the “tree” raises questions in our minds, does it not? Yes. For example, how could such a “tree” ever be chopped down? And this at the command of the Universal Sovereign, the Most High God himself? How is it set up again? God’s own written Word, the Holy Bible, explains.
32 For a long period of time Jehovah’s Universal Sovereignty was represented here on earth. How? Where? When? This was by means of the kingdom that he established over his chosen people, the twelve tribes of Israel. Particularly was this so when Jehovah’s anointed one, King David, was made king over all twelve tribes of Israel, after which he moved his capital city to Jerusalem, which he had captured from the pagan Jebusites. That was in 1070 B.C.E.
33 In that same year King David had the sacred Ark of the Covenant of Jehovah brought into the city and placed in a tent pitched near his royal palace. Thus, as it were, Jehovah began to reign in Israel’s capital Jerusalem, and the Israelite king was said to sit upon “Jehovah’s throne.” (1 Chronicles 29:23; 16:1-31) Repeatedly King David acknowledged Jehovah to be his heavenly King, the real Ruler of Israel. (Psalms 5:2; 24:7-10; 68:24; 145:1) Certainly, then, the kingdom centered at Jerusalem with David and his royal descendants sitting there on “Jehovah’s throne” represented Jehovah’s Universal Sovereignty with reference to our earth.—2 Chronicles 13:5, 8.
34 Logically that expression of Jehovah’s Universal Sovereignty as exercised through King David and his royal successors at Jerusalem was what was pictured by the immense tree seen in Nebuchadnezzar’s dream. In the dream, that all-dominating tree was chopped down. True to that dream, Divine Sovereignty as exercised through the line of Davidic kings at Jerusalem was chopped down, toppled, put out of operation. When? In 607 B.C.E., when Nebuchadnezzar of Babylon brought destruction upon Jerusalem and its temple and carried off its last enthroned king, Zedekiah of David’s family, into exile to die there. Jehovah himself had the symbolic tree of sovereignty chopped down, for he himself used Nebuchadnezzar as his “servant” to bring about this overthrow. Jehovah himself took the responsibility for overturning this visible expression of his sovereignty toward our earth.—Jeremiah 25:8-11, 17-29; Ezekiel 21:22-27.
35 At that time the bands of divine restraint as pictured by the bands of iron and copper were put around the remaining rootstock of the divine sovereignty as exercised through a royal descendant of King David. No royal sprout could come forth from this rootstock for the growing again of the divine sovereignty exercised through a Davidic king. For how long was this debased appearance of Jehovah’s Universal Sovereignty to continue? For “seven times,” which were prophetically illustrated by the “seven years” of Nebuchadnezzar’s dethronement for him to live like a beast of the field. So, how much time do “seven times” cover?
36 A “time” or lunar “year” used in connection with Bible prophecy averaged 360 days, that is, twelve lunar months averaging 30 days each. (Compare Genesis 7:11 through 8:4.) The “seven times” or “seven years” would therefore amount to 7 times 360 days, or 2,520 days. Are those 2,520 days to be understood literally in this case? Well, seven lunar years or 2,520 days after Jerusalem’s destruction in 607 B.C.E. and the leaving of her domain in the land of Judah desolate, Jehovah’s Universal Sovereignty with respect to our earth was not reestablished, was it? No! In the year 600 B.C.E. the surviving Israelites were still exiles in Babylon, Jerusalem and the land of Judah still lay desolate, and the Babylonian Empire was still the world power of the day. It was not till sixty-three years later, or in 537 B.C.E., that the exiled Israelites were given freedom by Babylon’s conqueror to leave, and reoccupy their beloved homeland. But, even then, the theocratic kingdom of the house of David was not set up again at Jerusalem.
37 The Medo-Persian Empire had now taken over world control as the Fourth World Power of Bible prophecy, and Cyrus the Great, the Persian, was emperor. So Zerubbabel, a legal and natural heir to David’s throne, was made merely the governor of the Persian province of Judah. Medo-Persia corresponded with the silver breasts and arms of the metallic image seen in the inspired dream that the prophet Daniel had to recall to Nebuchadnezzar’s mind and to interpret to him. (Daniel 2:31, 32, 39) According to that same dream and its interpretation, Gentile world control was to be exercised next by the copper-like Grecian World Power and then by the ironlike Roman Empire with an outgrowth therefrom in the form of the British-American Dual World Power of modern centuries. First after that, would Jehovah’s Universal Sovereignty (as pictured by the mountain) and the kingdom (pictured by the cut-out stone) interfere with the line of Gentile world powers. (Daniel 2:32-35, 44, 45) This brings us into our own twentieth century!
38 It is very evident, therefore, that the “seven times” of 2,520 days, as measured against the world-power “image,” from head to foot, must stand for something longer than the seven literal years of Nebuchadnezzar’s beastlike conduct, out in the field. So each of these 2,520 days must be treated according to the Bible rule: “A day for a year, a day for a year, is what I have given you.” (Ezekiel 4:6; compare Numbers 14:34.) This would mean that the “seven times” of domination of the earth by Gentile world powers without interference from God’s kingdom would extend for 2,520 years from the desolating of the land of Judah (including Jerusalem) by the Babylonians. That number of years from the middle of the seventh lunar month (or Tishri 15) of 607 B.C.E. leads up to when? To Tishri 15, or October 4/5, of 1914 C.E.
39 At that time Jehovah God the Almighty would loosen the iron and copper bands around the symbolic rootstock of Universal Sovereignty. Thus he would permit a royal “sprout” to grow up from it for the reestablishment of His Universal Sovereignty toward all the earth. (Job 14:7-9; Isaiah 11:1, 2) This took place in the birth of the “man child” government, foretold in Revelation 12:5-10 (AV;NW), which government was to “shepherd all the nations with an iron rod.” In Nebuchadnezzar’s dream of the world-power “image,” this event was pictured by the cutting of the “stone” out of the mountain with a view to its destroying the world-power “image.” (Daniel 2:34, 35) What a meaningful way that was of marking the end of the “appointed times of the nations,” the end of the “times of the Gentiles,” as foretold by Jesus Christ in Luke 21:24!—NW;AV.
40 From then on, the royal government that was represented by ancient Jerusalem under the kingship of David’s royal family was no longer to be “trampled on,” “trodden down,” by Gentile world powers. It was to trample them!
41 In view of all the foregoing, the Universal Governor, who knows the end from the beginning, foretold more than just Nebuchadnezzar’s time for being restored to the throne of the Babylonian World Power. Jehovah God foretold, simultaneously, the time for enforcing his own world rulership by a reasserting of his rightful Universal Sovereignty toward our earth. Having determined the time for this, we are now poised for considering the Chief Agent whom the Universal Sovereign Jehovah uses in this behalf. Shall we do so?
