(NewsNation) — Ukrainian forces have taken back more ground in their counteroffensive, advancing in areas Russia seized earlier in the conflict. That has Russian President Vladimir Putin upping the threats of a nuclear response if the Ukrainians continue pushing into provinces that Russia intends to annex.

Russian legislators in the lower house of the country’s parliament Monday approved the annexation of four regions of Ukraine: Kherson, Zaporizhzhia, Donetsk and Luhansk. This comes after annexation referendums from the Kremlin that the U.N. chief has described as illegal.

“What is happening in Ukraine will wind up hitting us here at home. It matters not only to Democratic ideals but to homeland security,” NewsNation’s Chris Cuomo said Monday night on “CUOMO.”

He added: “I spent time on the Ukrainian front lines, and it is amazing how American their ambitions are. Their appetite to be free of an oppressor is much like our fight versus England. Their fight may well become our own if the hostilities don’t end in Ukraine and soon.”

Former Clinton Defense Secretary William Cohen and former Trump National Security Adviser John Bolton joined “CUOMO” to break down the implications of Russia’s latest moves and explain what could happen in America if there aren’t changes in Ukraine.

Cohen says the proposition of annexation by Russia is dangerous because it’s more about power than law for Putin.

“Putin, number one, doesn’t believe in the law. We can say it’s illegal what he’s done, it’ll never be recognized,” Cohen said. “But Putin doesn’t care whether we recognize it or not. He cares about seizing it by power and then threatening with a retaliation that will make it unacceptable for the West to confront.”

Cohen believes that as Russian forces become weaker, the probability of Putin turning to nuclear weapons increases.

“That’s the danger we’re in now, everybody should recognize. I don’t think he’s bluffing. I think we’d have to take him seriously, and what we have to do is deter him as best we can,” Cohen said.

Bolton agreed, saying that Putin’s possible use of nuclear weapons becomes more realistic when his forces may be on the verge of collapse.

“I think we need to make it clear to Putin that if he did use a nuclear weapon, not only would there be severe consequences for the Russian military, there would be severe consequences for him,” Bolton said, later adding: “I think we should say publicly that if Putin did authorize the use of a nuclear weapon, he would be signing his own suicide note. I think that needs to be clear publicly so that everybody in the Russian military intelligence, domestic security conglomerate, knows how much is at risk here.”

Bolton insists that failures from the West are giving Putin and other countries the wrong message.

“If Putin can execute that maneuver and get away with it by staying in power, it is a terrible signal to Iran to North Korea, to China,” Bolton said. “I do think it’s worth considering exactly   how we’re going to try and deter Putin from doing that. Let’s face it, the fact this began in February means the West failed.”

Both Cohen and Bolton seem to agree that Putin using nuclear weapons could have a bad political impact. If that happened, it would mark the first atomic attack since 1945, according to reports.