NATO Steps Up to Watch Russian Subs Without the US

European countries are practicing how to track Russian nuclear submarines on their own as they worry about America's changing role in defense.

European members of NATO are getting ready to handle a big job on their own: tracking Russian nuclear submarines. For a long time, the United States has led the way in keeping an eye on these powerful underwater vessels. Now, as the U.S. role in European defense seems to be shifting, other NATO countries are stepping up. For the first time ever, the alliance held military exercises to practice hunting these submarines without any help from American forces. Why the worry? Russia has been updating its submarine fleet, making their boats faster and harder to find. These submarines are very qu…