Increasing antagonism with the US meant that Cuba was also looking to foil American plans abroad, and the Angolan crisis was a perfect opportunity for Cuba to use its strong military to embarrass the US.  Fidel Castro initially acted unilaterally and without notifying the Soviets on his intentions in Angola.  However, Cuban and Soviet collaboration soon led to highly effective assistance to the MPLA, with the Cubans provided tens of thousands of well-trained soldiers and the Soviets technical expertise and military equipment, particularly in the field of heavy artillery and tanks, which were previously absent in the Angolan theater.