Why will the Antichrist say whatever is needed to achieve his goals?
He will say whatever is needed because lying is his very makeup. His goal is to gain rule by flattery, intrigue, and political maneuvering, telling people what they want to hear. He even uses a deceptive treaty with Israel to promise peace and prosperity before turning on them.
Les explains that Daniel 11:21 leaps 2,500 years to this end-time individual, a vile person who does not receive the honor of a king by popular vote. Instead, he comes in with subterfuge, intrigue, and political maneuvering. He comes peaceably, not by violent overthrow, and rises to the top of the heap. He obtains his rule by flattery, saying what people want to hear and getting away with it. He is a liar because that is his very makeup; he will say whatever needs to be said to attain his ends. Les notes that verse 22 shows he signs a treaty with Israel through flattery, promising peace and prosperity, but then turns on them and brings violent pressure. Verse 36 adds that this king will do according to his will.
And in his estate shall stand up a vile person, to whom they shall not give the honour of the kingdom: but he shall come in peaceably, and obtain the kingdom by flatteries.