The destroyer completes a group of four based in the Mediterranean to provide Europe with a shield against attacks from ballistic missiles.
While the new ballistic missile defence (BMD) capability is primarily to deal with Iran, NATO chiefs have admitted it could be used against attacks from Islamic State (Isil) and Russia.
The ship’s arrival is also seen as an important recommitment of the US to its NATO allies in Europe.
Speaking to The Scotsman the captain of the Carney, Ken Pickard, said that it wad vital to renew the bonds of friendship between the US and European allies.
At a time when the new Labour leadership under Jeremy Corbyn is thought to want to quit NATO, Cdr Pickard provided a reminder of the importance of relationship for the US and Europe through NATO.
And as his ship, resplendent in bunting and flags, pulled into its home in Spain for the next five years, the port of Rota, he reminded his crew that they are “guests and ambassadors for the US” and to “treat your new home with respect.”
He also praised Faslane as “absolutely” important having visited there 15 years ago.
He added: “I received the best and most realistic training I have to date received there.”
He went on: “The word for it is beautiful. Its landscape, the people, the environment.”
The USS Carney joins the Porter, Ross and Donald Cook to complete phase one of the Aegis shield against ballistic and nuclear missiles.
Bases in Poland and Romania will provide the next two stages.
At a welcoming ceremony enlivened by families of the crew who have moved over from the USA, Admiral Mark Ferguson, commander of the sixth fleet in Europe and Africa, said that the system had been put in place to deal with Iran but repeated comments made by senior civilian representative Robert Bell from NATO that Islamic State could also get ballistic capabilities.
He also acknowledged that the system could defend against an attack from Russia, but “it had not been designed for that.”
He said that “7,000 tonnes of military capability” was a powerful symbol of the US’s commitment to Europe after concerns that it was focussing more in Asia.
The USS Carney, like her three sister ships, has the capability of waging war from deep sea to outer space with its state of the art kinetic missiles able to take out ballistic missiles.
Known by her 315 crew as “505 feet of fighting steel” the 19 year old ship named after a distinguished US admiral has been upgraded to become a multi weapons platform.
Her crew call themselves Carney Nation and she has a history of being one of the US’s best performing destroyers.