Why would the government lie about the shape of the earth?

Psalm 2:1-12 | Brenton Septuagint (LXX)

[1] Wherefore did the heathen rage, and the nations imagine vain things?
[2] The kings of the earth stood up, and the rulers gathered themselves together, against the Lord, and against His Christ;
[3] saying, “Let us break through their bonds, and cast away their yoke from us.”
[4] He that dwells in the heavens shall laugh them to scorn, and the Lord shall mock them.
[5] Then shall he speak to them in his anger, and trouble them in His fury.
[6] But I have been made king by Him on Sion His holy mountain,
[7] declaring the ordinance of the Lord: the Lord said to me, “Thou art my Son, today have I begotten thee.
[8] Ask of me, and I will give thee the heathen for thine inheritance, and the ends of the earth for thy possession.
[9] Thou shalt rule them with a rod of iron; thou shalt dash them in pieces as a potter’s vessel.
[10] Now therefore understand, ye kings: be instructed, all ye that judge the earth.
[11] Serve the Lord with fear, and rejoice in Him with trembling.
[12] Accept correction, lest at any time the Lord be angry, and ye should perish from the righteous way: whensoever His wrath shall be suddenly kindled, blessed are all they that trust in Him.