Forget 'Lame Duck' Obama, Watch Bernanke: Strategist

President Obama called an end to combat operations in IraqTuesday and said the focus is now on getting America’s economy back on track.

"Today, our most urgent task is to restore our economy, and put the millions of Americans who have lost their jobs back to work," Obama said. "This will be difficult. But in the days to come, it must be our central mission as a people, and my central responsibility as president."

But Obama is "now a lame duck and paralyzed" in his ability to use fiscal policy to influence the economy, Hans Redeker, the global head of foreign exchangestrategy at BNP Paribas, told CNBC Wednesday.

- Watch the full interview with Hans Redeker above.

"When you look at the outlook on fiscal side you have to look at what is happening at city and state level," Redeker said. "There is already fiscal tightening and Obama faces the same constraints given the democrats will lose power following mid-term elections."

"Under Clinton there was fiscal restraint once he lost power on capital hill two years into his presidency," he added.

Watch Bernanke and China

The chief player now is Federal Reserve Chairman Ben Bernanke and what the Fed does on quantitative easing this month.

"Monetary policy is the key," Redeker said. "The money multiplier is falling and you need to look at US domestic demand to understand where the global economy is going. We have seen some decoupling but America remains the dominant player and will influence global demand."

"The key is the velocity of money," he added. "Bernanke is the key to that and ahead of the curve, but he has to bring the rest of the FOMC with him when he moves in September."

The rest of the world remains very dependent on the US consumer and market sentiment will be dominated in September by the knock-on effects of slower US growthon China, Redeker said in a research note.

"So far, the epicenter of the 'post recession' weakness has been seen in the US, but spill-over effects to other geographical areas are developing," he said. "Asian leading indicators including consumer confidence and corporations' capital spending plans have eased, but it remains to be seen if hard data follow the decline in sentiment indicators."

"In this respect, upcoming Chinese data releases such as money and credit supply, consumer spending, industrial production and trade due for release on 9-14 September are likely to have a significant impact on investor sentiment and thus on the behavior of equity and commodity markets," he wrote.

"While we are confident that China will be able to defend its minimum 8 percent growth target, we see downside risks over the next couple of quarters," he added.