The captivity has started, and there’s no end of false prophets saying it won’t last very long. Hananiah is one:

Then the prophet Hananiah took the yoke-bars from the neck of Jeremiah the prophet and broke them. [See Jeremiah 27.1 – 10] And Hananiah spoke in the presence of all the people, saying, “Thus says the LORD: Even so will I break the yoke of Nebuchadnezzar king of Babylon from the neck of all the nations within two years.” But Jeremiah the prophet went his way. (Jeremiah 28.10, 11, ESV)

Jeremiah went his way rather than respond because hadn’t given him the response yet. When God did:

Go, tell Hananiah, “Thus says the LORD: You have broken wooden bars, but you have made in their place bars of iron. For thus says the LORD of hosts, the God of Israel: I have put upon the neck of all these nations an iron yoke to serve Nebuchadnezzar king of Babylon, and they shall serve him, for I have given to him even the beasts of the field.”

And Jeremiah the prophet said to the prophet Hananiah, “Listen, Hananiah, the LORD has not sent you, and you have made this people trust in a lie. Therefore thus says the LORD: ‘Behold, I will remove you from the face of the earth. This year you shall die, because you have uttered rebellion against the LORD.’ ”

In that same year, in the seventh month, the prophet Hananiah died. (Jeremiah 28.13 – 17, ESV)

We can’t manipulate God. We cannot do “positive affirmations” and change what God has decided.

This is the purpose that is purposed concerning the whole earth, and this is the hand that is stretched out over all the nations. For the LORD of hosts has purposed, and who will annul it? His hand is stretched out, and who will turn it back? (Isaiah 14.26, 27, ESV)