The US Navy in Europe is going dark.

The four destroyers in Rota, Spain, and ships operating in 6th Fleet are switching off their radars and sensors to operate with more stealth and train for fighting cyber and electronic attacks, said the Navy's top officer in Europe. said Wednesday.

"We need to change the culture in the surface Navy," said Adm. Mark Ferguson, head of Naval Forces Europe and a career surface warfare officer. "As I tell the [commanding officers] in Rota all the time, it's not a decision of what you turn off anymore, it's a decision of why you are turning something on. Why are turning that radar on? ... It has spurred tremendous creativity."

Ferguson told the crowd at the 2016 Surface Navy Association's national symposium last week that forces in Europe are operating almost constantly in some degree of emissions control, turning off radars and reducing communications to prevent jamming and to better mask their location and profile. That practice was routine during the Cold War and is returning as the US faces a newly aggressive Russian military.

"We're having to think about how are we going to get information to the ship if the satellite isn't there, if GPS is down — and we are running exercises where we take those systems away," Ferguson said. "We need to be able to execute the [ballistic missile defense] mission and fight through a network or cyber attack."

Ferguson also spoke about standing up the Aegis Ashore station in Romania, saying it was ready to perform rock but hasn't been certified yet.

"Everything works," he said. "It will fire, it will work great. The crews are in place and we are going through now getting worked up. You don't send a ship just out of pre[comissioning] out on deployment the first day, so we are working on the preparation to integrate this into the NATO architecture, and we are going to start breaking ground on Poland here real soon."

Aegis Ashore is an anti-ballistic missile defense system starting up in Romania to be sited in Poland. The first installation was built in Deveselu, Romania, on an old air base at the cost of about $1 billion.