Typically, no. However, in certain places around the world, fighter aircraft are assigned to protect assets involved in the Peacetime Aerial Reconnaissance Program (PARPRO). When I was in Korea in the early 90s, the 8th Fighter Wing at Kunsan picked up the PARPRO protection mission for RC-135s, EP-3s, U-2s and other assets flying strategic collection missions against North Korea.
I’m not aware of dedicated PARPRO protection assets for missions flows in the Baltic, with one important caveat. Since Lithuania, Estonia and Latvia joined NATO more than a decade ago, various alliance countries have deployed fighter aircraft and support personnel to bases in the Baltics on a rotating basis. Currently, this “air policing” mission is being performed by RAF Typhoons and F-16s from Portugal.
While the primary mission for these assets is defending Baltic airspace, they do respond to Russian provocations in the region. It was revealed earlier this year that air police fighters scrambled back in 2013 when the Russians staged a simulated nuclear strike mission against Sweden, and the Swedish Air Force was caught unprepared and couldn’t respond.
This past week, there was no indication the air police assets were scrambled when Russian jets buzzed the USS Donald Cook or looped that RC-135. Putin has correctly calculated that he will pay no price for such actions, and more incidents of this type are on the way.
“more incidents of this type are on the way.”
One wonders if the fighter “lit up” the RC135. Probably not, but the behavior may have been one step short of that. Like ISIS pulling up short on a beheading, the victim never knows when it is going to happen for real.
Let’s say that the Russians start positioning themselves on the ground for a possible invasion of a neighboring country, and when an RC135 is sent to look at it electronically, the Russians put a fighter on it’s tail. Is the invasion going to be real? The crew of the 135 could be the first to know when a threat indicator goes off.