The positive feelings driving strength in the stock market and the economy could disappear if any of the geopolitical trouble spots were to heat up, Starwood Capital's Barry Sternlicht said Wednesday.

He also cited the wranglings in Washington over tax reform as another layer of unpredictability.

"It feels like the ocean is full of money. But it feels like it could be yanked at any moment," the global investor and real estate specialist said on CNBC's "Squawk Box," citing North Korea or Syria as wildcards.

Whether President Donald Trump and GOP leaders on Capitol Hill can deliver on tax reform this year is also adding to uncertainty, said Sternlicht, co-founder, chairman and CEO of Starwood Capital, which has $55 billion in assets under management. And that uncertainty is manifesting itself in lower property transaction volumes as sellers wait to see if they might get to keep more of their capital gains a few months from now, he said.

Sternlicht said he's even put off projects within his own business for a quarter or so.

The White House and Republican House and Senate leaders are aiming to simplify and cut taxes on Americans and businesses by the end of the year.

"I think they will get something done. I just not don't think they'll get it done this year," Sternlicht said.

In a tweet Wednesday, Trump prodded lawmakers to "move fast" on taxes.

The approval process for the biggest Tax Cut & Tax Reform package in the history of our country will soon begin. Move fast Congress!

Sternlicht said he supports tax cut efforts but "you can't do tax reform in a tweet."

Treasury Secretary Steve Mnuchin on Tuesday made the case for tax changes, telling the CNBC-Institutional Investor Delivering Alpha conference that the administration is considering backdating tax reform to the beginning of 2017. Sternlicht said he was pleasantly "shocked" by the prospect of backdated tax cuts.

But the passage of tax reform depends on balancing the expected benefits to the economy and how to pay for it, he said.