Beyond the cheery faces and optimistic talk at last month’s Americas Lodging Investment Summit, an undertone of uncertainty and volatility went mostly unspoken. Nearly every conference speaker and person I interviewed only talked about the improving industry fundamentals and the vast opportunities for transactions this year and beyond. Of course, they were all right: 12 months ago no one could have definitively predicted how quickly travel has rebounded, leading to the remarkable industry turnaround. And Jones Lang LaSalle says hotel transactions volume will top $13 billion this year, up 80 percent from 2010 if you don’t count the sale of Extended Stay Hotels.

Yet, that’s only part of the story of the hotel business as we plunge further into 2011. Unlike any other recovery, the industry remains fragile because its underpinnings—the U.S. and world economies—remain tenuous. Credit is loosening (even the dormant CMBS market is reemerging), values are at or just above their low points and lots of deals—many forced upon owners in distress—will come to market. As Jay Shah of Hersha Hospitality told the ALIS crowd, “While you’ve got to evaluate things from market to market, it’s going to be a good year to be a net buyer of hotel assets.”

Even new development, especially of select-service properties, has a place in the lodging investment spectrum in 2011. Noble Investment’s Mit Shah, who has a reputation as a risk-taker, believes we’re in a “moment of time” when select-service development makes sense. As he pointed out, construction costs are down, land is available and many brands are more than willing to assist developers through credit enhancements or token investments.

Despite the widespread ebullience in the industry, smart executives and entrepreneurs are keeping an eye on the myriad factors that could hamper or even derail lodging’s comeback. The U.S. economy is most worrisome. While some signposts look promising (the Dow passed the 12,000 mark last month), others (unemployment above nine percent) are abysmal. No permanent economic recovery will arrive until people go back to work.

Even more troubling are global events. Nearly every brand company executive speaking at ALIS emphasized their firms’ international growth plans, a prospect that today doesn’t seem as secure as it did even six weeks ago. The crises in Tunisia and, more importantly, Egypt unmask the tenuous nature of operating and developing in countries outside the U.S. and Canada. The rewards of international growth are enormous, but so are the risks.

This year’s ALIS was a turning point for the industry, as last year’s uncertainty turned to this year’s hope and promise. Things look great for the hotel industry, as long as conditions beyond its control don’t conspire to negate a strong recovery.