(NewsNation) — Russia vowed Tuesday to scale back operations in Ukraine as the war wages on, but it is unclear what that means in practical terms. NewsNation sat down with Andrei Illarionov, a former advisor to Russian President Vladimir Putin to get an understanding of how the leader operates.

“The world needs to understand that this should be stopped. The sooner the better, because if he cannot be stopped in Ukraine he will go further,” Illarionov warned.

He says he is skeptical about a peaceful Russia-Ukraine resolution. Thousands of civilians were killed and more than 4 million people have fled the country since the start of the invasion on Feb. 24.

Illarionov is currently a Russian and economic expert, but his knowledge of the inner workings of the Kremlin and Putin comes from five years of working directly with the regime.

“Political regime became non-free. It became an authoritarian regime with a very high level of repression,” he told NewsNation.

Illarionov was Putin’s chief economic advisor up until 2005. When he resigned, he left the country and became an outspoken critic.

He says Putin has been planning the months-long invasion for years.

“He’s had this idea, this goal for last two decades. Even when I was his advisor, I was able to watch to see myself his intentions,” Illarionov said.

Illarionov says Putin could never accept the fact that Ukraine was its own sovereign nation separate from Russia. He believes the invasion is step one in Putin’s grand plan of reunifying the whole former Soviet Union.

Peace talks in Istanbul Tuesday were focused on securing a cease-fire and guarantees for Ukraine’s security, issues that have been at the heart of previous unsuccessful negotiations.

U.S. Secretary of State Antony Blinken said he had not seen anything indicating talks were progressing in a “constructive way,” and he suggested Russian indications of a pullback could be an attempt by Moscow to “deceive people and deflect attention.”

He added, “If they somehow believe that an effort to subjugate only the eastern part of Ukraine or the southern part of Ukraine … can succeed, then once again they are profoundly fooling themselves.”

Illarionov agrees.

“So far I have not seen anything that Putin would say,” he said. “But even when he makes some promises, it does not mean that he’s going to execute them first.”

Like Illarionov, many Ukrainians and leaders in the west say they will trust the actions of the Russian military to end the war and not the claims of Putin.