Ever since Russia’s military annexation of Crimea in 2014, tensions between Vladimir Putin’s regime and NATO forces on Europe’s eastern flank have been on the rise. While the combined military might of the NATO alliance should be able to route a Russian offensive against Europe, concerns remain even the recently bolstered NATO force couldn’t prevent Russia from capturing the narrow stretch of land between Kaliningrad and their ally Belarus, physically severing supply lines to the Baltic states.

Baltic defense has been among the priorities of NATO’s expansion of forces throughout Europe, but one of the biggest obstacles facing these defensive forces is the broad expanses of territory to cover. With so much border territory, NATO has been forced to spread defensive assets fairly thin and adopt a strategy of rapidly intercepting a Russian incursion and holding it off until reinforcements can arrive. In this hypothetical offensive, Russian forces would undoubtedly outnumber NATO forces at the onset of the fight, but NATO hopes to offset that advantage with a fast and coordinated international response.

Of course, that means speed in the name of the game, when it comes to European defense – and last month, the U.S. Army put itself to test to see how effectively it could meet the needs of America’s allies in the event of a Baltic invasion.

Soldiers assigned to the 82nd Brigade Engineer Battalion out of Fort Riley, Kansas were given less than 48 hours notice to coordinate a response in Estonia, some 1,500 miles away from where they’re currently deployed as a part of NATO’s response forces. The effort required significant cooperation across military and civilian channels, as they assembled a force comprised of Nuclear, Biological, Chemical reconnaissance vehicles, as well as other essential military equipment from several nearby nations.