Britain joined the U.S. and its allies in the fight against ISIS -- but any mission will come with a huge price tag. The UK parliament has approved airstrikes in Iraq against the terror group which prime minister David Cameron has called one of "staggering"  brutality. Cameron had said Britain should join international allies in combating ISIS, an action that he warned would "take not just months, but years." While the total cost will depend on the intensity and length of operation, past experience can give some guidance, Malcolm Chalmers, research director from the Royal United Services Institute said. Chalmers pointed to the UK's seven month involvement in Libya through 2011, which cost around $390 million, including missiles and flight hours.
@highlight
UK can start bombing ISIS within hours, as it has six fighter jets on standby in Cyprus
@highlight
British forces have Brimstone precision missiles, high-tech weapons others don't have
@highlight
The U.S. is leading the airstrikes against ISIS in Iraq and Syria
Chalmers said he would expect the cost of @placeholder airstrikes to be in the "ballpark," of the Libya operation, "assuming we only use air power and the campaign lasts for a couple of years."