(NewsNation) — A NewsNation/Decision Desk HQ poll found there is broad support for continuing to arm the Ukrainians in their fight against Russia, as well as for the economic sanctions imposed by the United States. But Americans draw a line: They are almost as strongly against using U.S. troops to defend Ukraine.

So, the question remains: What leverage beyond sanctions can stop Russian President Vladimir Putin from invading Ukraine? NewsNation’s ‘On Balance” host Leland Vittert, who reported from Ukraine during the outbreak of the conflict there in 2014, shared his thoughts Thursday on “Morning in America.”

“It has become a clear that the White House’s overarching principle is do not provoke a Vladimir Putin,” Vittert said. He says the Biden administration will not do anything to incite World War III. Vittert says people in Europe and Germany feel the same way.

Still, 52% of respondents in the NewsNation/Decision Desk HQ poll identify Russia as the nation’s largest threat, more so than China.

He says the U.S. and its allies have a few more options to punish Putin for the war.

“You could sanction his energy industry, because that still has not happened. He can still sell oil and gas around the world. You could give MiG fighters to the Ukrainians, anti-ship missiles, or sanction Vladimir Putin personally rather than the oligarchs around him,” Vittert said.

Vittert says fear of provoking Putin looms across the U.S. and Europe.

“Clearly, that fear of provoking him has not stopped him from invading Ukraine and committing atrocities,” he said.

Wednesday night, the U.S. House passed a massive spending bill that includes $13.6 billion in aid for Ukraine and its European allies.

On Thursday, Vice President Kamala Harris, from Poland, called for an international war crimes investigation of Russia.

Read the full NewsNation poll results here.