VENTSPILS, Latvia-U.S. Sailors with Navy Cargo Handling Battalion One, conduct the off-loading of tanks during exercise Saber Strike 17 in Ventspils, Latvia, May 23, 2017 Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Lance Cpl. Ricardo Davila/Released) - VENTSPILS, Latvia-U.S. Sailors with Navy Cargo Handling Battalion One, conduct the off-loading of tanks during exercise Saber Strike 17 in Ventspils, Latvia, May 23, 2017 Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Lance Cpl. Ricardo Davila/Released)

VENTSPILS, Latvia- NATO nations participate in convoy operations alongside Marines while escorted by Latvian Movement and Control officers during exercise Saber Strike 17 in Ventspils, Latvia, May 28, 2017. Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. - VENTSPILS, Latvia- NATO nations participate in convoy operations alongside Marines while escorted by Latvian Movement and Control officers during exercise Saber Strike 17 in Ventspils, Latvia, May 28, 2017. Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats.

ADAZI, Latvia-Marines with the Black Sea Rotational Force 17.1 stand in formation as the flags of some of the participating nations are raised to the Latvian National Anthem during the opening ceremony of Exercise Saber Strike 17 at Camp Adazi, Latvia, June 3, 2017. The combined training prepares NATO Allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Cpl. Devan Alonzo Barnett/Released) - ADAZI, Latvia-Marines with the Black Sea Rotational Force 17.1 stand in formation as the flags of some of the participating nations are raised to the Latvian National Anthem during the opening ceremony of Exercise Saber Strike 17 at Camp Adazi, Latvia, June 3, 2017. The combined training prepares NATO Allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Cpl. Devan Alonzo Barnett/Released)

VENTSPILS, Latvia - U.S. Sailors with Navy Cargo Handling Battalion One, conduct the off-loading of tanks during exercise Saber Strike 17 in Ventspils, Latvia, May 24, 2017. Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Lance Cpl. Ricardo Davila/Released) - VENTSPILS, Latvia - U.S. Sailors with Navy Cargo Handling Battalion One, conduct the off-loading of tanks during exercise Saber Strike 17 in Ventspils, Latvia, May 24, 2017. Exercise Saber Strike 17 is an annual combined-joint exercise conducted at various locations throughout the Baltic region and Poland. The combined training prepares allies and partners to respond more to regional crises and meet their own security needs by improving the security of borders and countering threats. (U.S. Marine Corps photo by Lance Cpl. Ricardo Davila/Released)