In the beginning of 1991 , Croatia had no regular army . In an effort to bolster its defence , Croatia doubled the size of its police force to about 20 @,@ 000 . The most effective part of the force was the 3 @,@ 000 @-@ strong special police that were deployed in 12 battalions , adopting military organisation . In addition there were 9 @,@ 000 – 10 @,@ 000 regionally organised reserve police . The reserve police were set up in 16 battalions and 10 companies , but they lacked weapons needed to arm many of the troops .