In later campaigns, the Croatian army would pursue a variant of blitzkrieg tactics, with the Guard brigades punching through the enemy lines while the other units simply held the lines at other points and completed an encirclement of the enemy units. In a further attempt to bolster its armed forces, Croatia hired Military Professional Resources Inc. (MPRI) in September 1994 to train some of its officers and NCOs. Begun in January 1995, MPRI's assignment involved fifteen advisors who taught basic officer leadership skills and training management. MPRI activities were reviewed in advance by the US State Department to ensure they did not involve tactical training or violate the UN arms embargo still in place.