Somehow the American economy appears to be getting better, even as the rest of the world is looking worse.

In the midst of the European debt crisis, lingering instability in the oil-rich Middle East and concerns about a Chinese economic slowdown, the American unemployment rate unexpectedly dropped last month to 8.6 percent, its lowest level in two and a half years.

The Labor Department also said that the nation’s employers added 120,000 jobs in November and that job growth for the previous two months was better than initially reported. That looks like good news for President Obama as he heads into the 2012 presidential election — especially since just a few months ago the picture looked bleak.

“If you go back to August, all sorts of people were telling us that the economy was headed straight into recession,” said Paul Ashworth, senior United States economist at Capital Economics. “Since that point, we’ve become more and more worried about the euro zone and other areas of the global economy, but somehow, at least for the moment, the U.S. economy seems to be shrugging all that off.”