Complex sentence: They signed a contract with local Naga insurgents on 2 June 1973 that established terms for supplying military training and arms by KIA and the organization of the Naga region according to tradition.
Split into simpler sentences: They signed a contract with local Naga insurgents on 2 June 1973. This laid out the terms on supplying military training and arms by KIA and the organization of the Naga region according to tradition.