It depends what you mean by the end days.
There will not be a one world government until Jesus Christ returns to judge the world and restore the kingdom of David as the kingdom of God on Earth.
Before Christ returns there will not be a one world government.
The nations will have separate governments when they are gathered to Armageddon.
Armageddon consists of an invasion of Israel by a confederacy of nations from the north as described in Ezekiel 38 and 39.
This will be opposed by maritime nations described as the merchants of Tarshish.
Ezekiel 38:2 Son of man, set thy face against Gog, the land of Magog, the chief prince of Meshech and Tubal, and prophesy against him, 3 And say, Thus saith the Lord GOD; Behold, I am against thee, O Gog, the chief prince of Meshech and Tubal: 4 And I will turn thee back, and put hooks into thy jaws, and I will bring thee forth, and all thine army, horses and horsemen, all of them clothed with all sorts of armour, even a great company with bucklers and shields, all of them handling swords: 5 Persia, Ethiopia, and Libya with them; all of them with shield and helmet: 6 Gomer, and all his bands; the house of Togarmah of the north quarters, and all his bands: and many people with thee. 7 Be thou prepared, and prepare for thyself, thou, and all thy company that are assembled unto thee, and be thou a guard unto them. 8 After many days thou shalt be visited: in the latter years thou shalt come into the land that is brought back from the sword, and is gathered out of many people, against the mountains of Israel, which have been always waste: but it is brought forth out of the nations, and they shall dwell safely all of them. 9 Thou shalt ascend and come like a storm, thou shalt be like a cloud to cover the land, thou, and all thy bands, and many people with thee. 10 Thus saith the Lord GOD; It shall also come to pass, that at the same time shall things come into thy mind, and thou shalt think an evil thought: 11 And thou shalt say, I will go up to the land of unwalled villages; I will go to them that are at rest, that dwell safely, all of them dwelling without walls, and having neither bars nor gates, 12 To take a spoil, and to take a prey; to turn thine hand upon the desolate places that are now inhabited, and upon the people that are gathered out of the nations, which have gotten cattle and goods, that dwell in the midst of the land. 13 Sheba, and Dedan, and the merchants of Tarshish, with all the young lions thereof, shall say unto thee, Art thou come to take a spoil? hast thou gathered thy company to take a prey? to carry away silver and gold, to take away cattle and goods, to take a great spoil?
Zechariah describes it thus:
Zechariah 14:2 For I will gather all nations against Jerusalem to battle; and the city shall be taken, and the houses rifled, and the women ravished; and half of the city shall go forth into captivity, and the residue of the people shall not be cut off from the city.
This will precipitate the return of Christ.
3 Then shall the LORD go forth, and fight against those nations, as when he fought in the day of battle. 4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south. 5 And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the LORD my God shall come, and all the saints with thee.
This is shown in a vision to Daniel as a stone hitting an image of the kingdoms of men.
Daniel 2:34 Thou sawest till that a stone was cut out without hands, which smote the image upon his feet that were of iron and clay, and brake them to pieces. 35 Then was the iron, the clay, the brass, the silver, and the gold, broken to pieces together, and became like the chaff of the summer threshingfloors; and the wind carried them away, that no place was found for them: and the stone that smote the image became a great mountain, and filled the whole earth.
44 And in the days of these kings shall the God of heaven set up a kingdom, which shall never be destroyed: and the kingdom shall not be left to other people, but it shall break in pieces and consume all these kingdoms, and it shall stand for ever.
This will be the beginning of Christ’s thousand-year reign over the mortal population of the earth.
At his return, he will raise the faithful out of their graves and give them eternal life and they will rule with him.
This is called the first resurrection.
Revelation 20:6 Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with him a thousand years.
During this time wars will cease.
Isaiah 1:1 ¶ The word that Isaiah the son of Amoz saw concerning Judah and Jerusalem. 2 And it shall come to pass in the last days, that the mountain of the LORD’S house shall be established in the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it. 3 And many people shall go and say, Come ye, and let us go up to the mountain of the LORD, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the LORD from Jerusalem. 4 And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more.
Following the millennial reign there will be a second resurrection and a final judgment. Sin and death will be eradicated. Those raised and rejected at the judgment will die again (the second death) and perish forever. All who live on will receive the divine nature. God will live in and with his people forever.
Paul explains what is going to happen:
1 Corinthians 15:20 But now is Christ risen from the dead, and become the firstfruits of them that slept. 21 For since by man came death, by man came also the resurrection of the dead. 22 For as in Adam all die, even so in Christ shall all be made alive. 23 But every man in his own order: Christ the firstfruits; afterward they that are Christ’s at his coming. 24 Then cometh the end, when he shall have delivered up the kingdom to God, even the Father; when he shall have put down all rule and all authority and power. 25 For he must reign (the millennial reign), till he hath put all enemies under his feet. 26 The last enemy that shall be destroyed is death. 27 For he hath put all things under his feet. But when he saith all things are put under him, it is manifest that he is excepted, which did put all things under him. 28 And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all.
God made the earth to be inhabited.
Isaiah 45:18 For thus saith the LORD that created the heavens; God himself that formed the earth and made it; he hath established it, he created it not in vain, he formed it to be inhabited: I am the LORD; and there is none else.
He intends to fill the earth with his glory.
Numbers 14:21 But as truly as I live, all the earth shall be filled with the glory of the LORD.
God’s glory will be in the form of men and women raised to the divine nature.
2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
Revelation describes this time:
Revelation 21:3 And I heard a great voice out of heaven saying, Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God. 4 And God shall wipe away all tears from their eyes; and there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.
May I suggest that you read: ‘The Kingdom of God on Earth’ here:
And ‘Your Share in God's Promises’ here:
I hope you find this helpful.