(NewsNation) — At the time, tough sanctions and strong rebukes seemed to do the trick against Russian President Vladimir Putin. But now, the former U.S. ambassador to Ukraine says America should have done more in 2014 to prevent the war of 2022.

“We should have provided a lot more security assistance,” Marie Yovanovitch said Monday on “Banfield.”

Yovanovitch was not America’s ambassador to Ukraine when Putin annexed Crimea and sponsored pro-Russian separatists in eastern Ukraine in 2014. But she says she supported Barack Obama’s response at the time. The U.S. imposed sanctions and pushed to remove Russia from what was then the G8 (now the G7).

Putin’s hold on Crimea persisted, though it was in geopolitical dispute. The United States does not recognize Crimea as part of Russia, and some have speculated Putin only annexed it to make NATO uneasy at the thought of admitting Ukraine.

Punishing Russia has always been a delicate proposition. Their oil supply is crucial to European countries, and they have thousands of nuclear weapons. It’s why some recoiled when President Joe Biden said Putin “cannot remain in power” during a speech to troops in Poland over the weekend.

“The speech itself will be remembered as a seminal piece of oratory that laid out our interests, values, defense of NATO, support for Ukraine,” Yovanovitch said. “It was a direct appeal to the Russian people that this war is not worthy of them, given how they suffered during World War II.”

Yovanovitch praised Ukrainian President Volodymyr Zelenskyy for his leadership during the war.

“He is reflecting his people, the will to exist, when the Russians are invading their country, bombing their homes, killing the children — it’s apalling,” she said on “Banfield.”