Ukrainian president Zelensky to address U.S. Congress

Ukrainian President Volodymyr Zelenskyy's address to Congress Wednesday reflects the reality of the NATO alliance and the importance of getting the United States' backing for any additional action against Russia's invasion.

"The European countries do not want to be engaged militarily without the United States backing them and doing the heavy lifting," said UC Berkeley political science professor George Breslauer, "Any visible disunity is going to embolden Moscow to play parts of NATO against each other."

President Zelenskyy is facing a mounting civilian death toll as Russia continues attacks, including one at a base in western Ukraine very close to Poland a NATO member.

President Biden has drawn a line at NATO countries' borders, saying the U.S. will defend NATO territory but won't venture into Ukraine.

"I think he's made the decision. No boots on the ground. And while the Congress has the power to initiate a war, I don't know if there is the interest in walking down that path," said Congresswoman Jackie Speier (D-San Mateo) who sits on the House Armed Services and Intelligence committees. Rep. Speier says the United States for now is not planning to intervene in negotiations but plans to continue with military support and harsh economic sanctions against Russia.

"It is a full-blown depression in just a matter of two weeks in Russia and for us to negotiate would require us to lift sanctions and I don't think we're prepared to do that yet," said Rep. Speier.

The sanctions on Russian oligarchs, however, likely will not impact Putin's actions according to Breslauer.

"He's meeting privately, with primarily just a few of his highest security associates," said Breslauer, "Putin is at this point militarily testing the limits. I expect him to test the limits of diplomacy as well."

Breslauer says Putin will drive a hard bargain in negotiations.

"When Zelenskyy talks about a compromise he talks about a pledge not to join NATO. When Putin talks about a compromise, he talks about that, plus Ukrainian demilitarization which would leave them without an army," said Breslauer, adding that Putin would also likely push for parts of Ukraine to be occupied by Russia.

There's also concern Putin might have an ally in China. U.S. sources indicated Tuesday that China might be signaling support for Russia's military. China and Moscow denied any deal. The possibility of such an alliance, however, is prompting a question of whether the U.S. would punish China with sanctions.

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"The reality is it would hurt American business and American consumers, but it would devastate China which has a trade deficit of $700 billion of exports to the United States, so I don't think this is a road we want to go down," said Congressman Ro Khanna, a member of the House Armed Services Committee who represents Silicon Valley.

Rep. Khanna says he thinks China should be punished if it provides military support for Russia's invasion but hopes that aggressive diplomacy would help avoid sanctions.

President Biden plans to go to Europe to meet with NATO leaders in Brussels next Thursday.

Jana Katsuyama is a reporter for KTVU.  Email Jana at jana.katsuyama@fox.com and follow her on Twitter @JanaKTVU or Facebook @NewsJana or ktvu.com.