It's never good for a company to upset its biggest customer, much less one that accounts for more than 80% of its revenue. But it appears that's exactly what Lockheed Martin has done with the U.S. government, with one Air Force major general calling the relationship "the worst I've ever seen."

Clearly, this is not good news for Lockheed and the largest defense contract ever, the F-35 Joint Strike Fighter. But what does this mean for investors? Probably not a whole lot, at least right now. It's in both parties' interest to move as quickly as possible on this delayed project.

Still, investors should watch for any further deterioration of the relationship, especially as the Pentagon and Lockheed brace for sequestration that could go into effect in January. Check out the following video for more on Lockheed and the defense industry as a whole.

The uncertainty over sequestration has scared many investors away from Lockheed Martin. But if you're looking for some other great ideas outside the defense sector, we've compiled a new free report, "The Motley Fool's Top Stock for 2012." In it, our chief investment officer identifies his favorite company for the year. To access the report before the rest of the market catches on, click here -- it's absolutely free.