The Sea-Air-Space Exposition opened in Maryland yesterday. It is one of the U.S. defense industry's largest trade shows--a place where government agencies and private-sector companies gather to peruse the shiniest and most fearsome new military equipment. It is also a good barometer of where the industry is headed. Here are the four most important trends I spotted:

Cameras. Everywhere.
The sheer number of cameras, sensors, sonar systems, and other surveillance equipment was overwhelming. I was expecting to see a lot of weapons here; I was not expecting the guns and missiles to be outnumbered by fancy new cameras.