Why, in the other books of the Bible, is the phrase, "the east", understood to mean, apparently east of Israel?

Genesis 11:2 And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there.

Genesis 25:6 But unto the sons of the concubines, which Abraham had, Abraham gave gifts, and sent them away from Isaac his son, while he yet lived, eastward, unto the east country.

Genesis 29:1 Then Jacob went on his journey, and came into the land of the people of the east.

Judges 6:3 And so it was, when Israel had sown, that the Midianites came up, and the Amalekites, and the children of the east, even they came up against them;

I Kings 4:30 And Solomon’s wisdom excelled the wisdom of all the children of the east country, and all the wisdom of Egypt.

Job 1:3 His substance also was seven thousand sheep, and three thousand camels, and five hundred yoke of oxen, and five hundred she asses, and a very great household; so that this man was the greatest of all the men of the east.

Isaiah 11:14 But they shall fly upon the shoulders of the Philistines toward the west; they shall spoil them of the east together: they shall lay their hand upon Edom and Moab; and the children of Ammon shall obey them.

Isaiah 41:2 Who raised up the righteous man from the east, called him to his foot, gave the nations before him, and made him rule over kings? he gave them as the dust to his sword, and as driven stubble to his bow.

Isaiah 43:5 Fear not: for I am with thee: I will bring thy seed from the east, and gather thee from the west;

Isaiah 46:11 Calling a ravenous bird from the east, the man that executeth my counsel from a far country: yea, I have spoken it, I will also bring it to pass; I have purposed it, I will also do it.

Jeremiah 49:28 Concerning Kedar, and concerning the kingdoms of Hazor, which Nebuchadrezzar king of Babylon shall smite, thus saith the LORD; Arise ye, go up to Kedar, and spoil the men of the east.

Ezekiel 25:4 Behold, therefore I will deliver thee to the men of the east for a possession, and they shall set their palaces in thee, and make their dwellings in thee: they shall eat thy fruit, and they shall drink thy milk.

Zechariah 8:7 Thus saith the LORD of hosts; Behold, I will save my people from the east country, and from the west country;

Matthew 2:1 Now when Jesus was born in Bethlehem of Judaea in the days of Herod the king, behold, there came wise men from the east to Jerusalem,

  2 Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him.

But then, suddenly, in the last book, in chapter 16, why do people say that kings of the east then must be referring to China, Vietnam, North Korea, etc?

Revelation 16:12 And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared.

Unless Jacob journeyed to Vietnam, Job was North Korean, and the wise men were Chinese?

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