contingent

sattumanvarainen

riippuva

osasto

joukkue

mahdollinen An event which may or may not happen; that which is unforeseen, undetermined, or dependent on something future; a contingency.
That which falls to one in a division or apportionment among a number; a suitable share; proportion.
puhekieltä A quota of troops.
2014, Ian Black, "http://www.theguardian.com/world/2014/nov/27/-sp-courts-jordan-crush-support-isis Courts kept busy as Jordan works to crush support for Isis", The Guardian, 27 November 2014:

Arrests and prosecutions intensified after Isis captured Mosul in June, but the groundwork had been laid by an earlier amendment to Jordan’s anti-terrorism law. It is estimated that 2,000 Jordanians have fought and 250 of them have died in Syria – making them the third largest Arab contingent in Isis after Saudi Arabians and Tunisians.

The success of his undertaking is contingent upon events which he cannot control.

a contingent estate