China is making a big deal out of a supposed overflight by a U.S. Air Force U-2 spy plane of one of its currently underway People's Liberation Army Navy (PLAN) exercises.

The Chinese could see the U-2 coming from far away and the aircraft has one of the world's most capable electronic warfare self-protection suites. The potential payoffs of pushing one of these spy planes directly over or near a Chinese live-fire naval exercise are also quite high. The aircraft could suck up all of the PLAN's radar, data-links, and other communications signatures, as well as eavesdrop on its voice communications and monitor its operational procedures. Just how the PLAN would respond to the U-2 being there and what sensors would track it could dramatically increase the fidelity of this intelligence value, as well. In other words, it would both stimulate and surveil the PLAN's integrated air defense capabilities. 

It's also worth noting that China has no fighter aircraft capable of physically intercepting a U-2 and harassing it. That doesn't mean they don't have the capability to shoot one down though, but an incident like the one that occurred off of Hainan Island in 2001, which involved a much lower-flying U.S. Navy EP-3E Aries II spy plane, wouldn't be a factor when employing a U-2. 

While China can issue a notice to airmen (NOTAM) warning of live-fire drills, the vast majority of the exercise would have taken place in international waters. So, the U-2 may have waltzed into or near China's air defense identification zone, and the airspace it 'closed' for the exercise, but that doesn't mean it broke any territorial boundaries.

Want to play with the big boys, Commies?  Then expect a big boy response.  What whiners.