In the first half if 2015, the marines have completed nine major exercises and 46 military-to-military engagements, compared to just six exercises and 22 military-to-military engagements during the previous rotation, Ukraine Today reports.

The new iteration of Black Sea Rotational Force, including 150 marines, equipped with four Abrams main battle tanks, six light armored vehicles and three howitzers, will be based in Bulgaria.

Marines will not only serve as a deterrent, but swap best practices with allies' troops in Eastern Europe.

Bulgaria borders the Black Sea, also bordered by Russia, therefore Marines will be just a few hundred miles from the Russian-annexed Crimean peninsula.

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