Richard Fisher is a senior advisor at Barclays and was president of the Federal Reserve Bank of Dallas from 2005 to 2015.

He says the economy "is having the longest period of expansion since the Civil War" and expects that to continue — for now.

But he also sees potential challenges ahead. Fisher says a "hyper-leveraged government" issuing even more U.S. Treasury bonds next year, the Fed raising rates, and potential dangers from bad credit in the European Union could cause a slowdown.

Watch the video above for more from Richard Fisher and the video below for his take on the biggest long-term threat to the economy.