WASHINGTON – The U.S. economy shrank unexpectedly late last year, a reminder of the biggest threat it faces in 2013: sharp government spending cuts and prolonged political budget fights.

A plunge in defense spending helped push the economy into negative territory for the first time since mid-2009. The contraction in the October-December quarter came in at an annual rate of 0.1 percent, according to a government estimate released Wednesday.

The likelihood of another recession appears remote. The economy is forecast to grow around 2 percent this year as strength in areas such as housing and auto sales could partly offset government cutbacks. Investors appear unfazed, too: The stock market has surged more than 6 percent this year and is nearing an all-time high.