'A cornered Putin' isn't done with economic retaliation and could cut oil exports to Europe before embargo kicks in, RBC Capital's Helima Croft says

• Vladimir Putin is cornered and dangerous, raising the odds of more economic retaliation, RBC Capital's Helima Croft told CNBC Wednesday.
• The commodities strategist warned that Russia could slash oil deliveries ahead of December when the EU's partial embargo kicks in.

Russian President Vladimir Putin can still lash out against Europe's economy with a surprise cut in oil exports, according to Helima Croft, RBC Capital Markets' head of global commodity strategy.

After his military suffered devastating defeats in Ukraine recently, Putin announced the mobilization of 300,000 more troops early Wednesday and hinted at the use of nuclear weapons. He may not stop there.

"A cornered Putin is a very dangerous Putin, and we should prepare for very destabilizing, escalatory moves from this regime," Croft told CNBC Wednesday, though she noted that traders seem more concerned about the Federal Reserve than Russia this week.

For example, Putin may move to cut oil exports ahead of the December 5 start-date for Europe's partial embargo on Russian crude, she warned.

Oil is Moscow's main source of revenue, but slashing supplies could be a way to tighten global markets and raise prices.

"It's not like Vladimir Putin would go to zero, but he's already facing the prospect of being locked out of Europe by December 5," Croft maintained. "All he has to do is start pulling back early, essentially saying to Europe, 'You're going to cut me off December 5? I'm going to cut you off now.'"

Meanwhile, Russian seaborne oil exports dropped to their lowest level in a year, as Europe cuts back while Asian customers aren't making up the difference. In the first two weeks of September, exports totaled 3.03 million barrels per day, down by about 314,000 barrels per day compared to August, Kpler data shows.

Last month, Rystad Energy forecasted that Russian oil output would soon fall by over 1 million barrels per day as demand from China and India wanes and the EU ban begins.

Nonetheless, to Croft, if Russia makes a decision to reduce crude deliveries, it would ultimately raise the stakes in the ongoing game of brinkmanship.

"I think there are many more cards Putin can play and I'm not sure he's done by any means on the economic front," she said.