The United States and NATO have been "intimidated by the Russians" by the threat of tactical nuclear weapons use, and they need to define clear objectives to "win the war" for Ukraine and tell Vladimir Putin that using nukes will cost him his life, according to former National Security Adviser John Bolton.

"We're intimidated by the threat of tactical nuclear weapons," Bolton told The Sunday Times radio in an interview Saturday. "I think for one year, Putin has bluffed. It's been entirely an effort to psyche out the United States and the West, and it's succeeded.

"I think we need to make it clear to the Russians generally that any use of tactical nuclear weapons would result in devastating retaliation, including a direct attack on Vladimir Putin's life personally.

"Now, if there's a better way to deter Putin, I'm happy to hear about it. But what I'm looking for is the most convincing argument to convince the Russians that they can just leave their tactical nuclear weapons in their arsenals where they are now."

The time for slow-walking aid to Ukraine against Putin should end, Bolton argued, saying both the U.S. and NATO need to pay up, define clear war objectives to entirely free Ukraine — including Crimea — and drive every Russian soldier out of the country.

"We have not provided adequate weaponry to the Ukranians," Bolton said. "We don't not have a strategy to win.

"It really endangers support for the war, at least in the United States, when we're afraid to say conclusively that our objectives are the removal of all Russian troops and the restoration of full Ukranian territorial integrity and sovereignty — meaning and including Crimea."

That means NATO — which showed up "pathetically weakly in response to the first invasion" — needs to kick its support up to 4% of Gross Domestic Product, too, and move to "restore NATO's credibility," Bolton added.

"We need substantially greater defense expenditures across the board," he continued. "The 2% NATO target is inadequate. It ought to be 3% or 4% of GDP."

And all this needs to happen in a "timely fashion," so the world can avoid the Russian aggression in Ukraine becoming a war of attrition that the larger country ultimately wins, according to Bolton.

"The notion we can have defense and deterrence on the cheap has been brutally destroyed by Russia's aggression," Bolton said in his call for war and spending. "Let's learn the lesson. It's right in front of us.

"Let's win the war. If that's what our objective is, let's tell the people of our countries, and let's get on with it."

Bolton added Putin is "all-in now" and "this is not a European war anymore; this is a global war," pointing to China's growing support for Russia.

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