There can be no let up in the campaign against Islamic State or the extremist group could come "bouncing back", the head of the Royal Air Force has warned.
RAF jets alongside Reaper drones have carried out more than 1,700 strikes, as well as surveillance and reconnaissance missions since efforts to eradicate the group began.
Air Chief Marshal Sir Stephen Hillier said even though the jihadis have lost 98% of the territory they once held, a drawdown of RAF efforts is not on the horizon.
"The key thing here is, as we have discovered in previous conflicts, is that if we let up, then they will come bouncing back, and we will have to re-engage," he told the Press Association.
"We will have to keep going with this one until the job is done. When people say to me 'when is that going to be?' Well, when it is done."
In 2014 the group blitzed across vast swathes of Syria - seizing Raqqa - before spreading into north and western Iraq, capturing Mosul and even advancing to the edges of Baghdad.
Since then the US-led 74-member global coalition has worked to destroy the extremists - seeing Mosul liberated in July and Raqqa in October as result of the efforts.
But Air Chf Mshl Hillier revealed that even though the spread of the group has been "stopped and rolled back", the jihadis could "morph into something different".
"They are starting to look more like an insurgent terrorist organisation who are trying within that region and more widely across the world to undermine us by other means," he said.
"That starts to feel more like what we experienced in Afghanistan and Iraq before.
"What it indicates is that you need to have the understanding, the capability to find these people and you need to have the ability to deal with them as necessary when you do find them.
"I don't see any drawdown as a result of that, and it is not because I cannot see into the future.
"I simply look at the RAF as being continually involved in these sorts of operations for nearly three decades now - that tells us something about what the world is like.
"I anticipate that it is going to keep looking like that, different pressures but more likely to be on reconnaissance than on the strike capability, but we will still need to have both of them there throughout."
Air Chf Mshl Hillier said there is a "spectrum" of threats facing Britain when quizzed on what the biggest security issues facing the country are.
"At one end of the spectrum we have the need to counter violent extremist organisations - Daesh are probably one of the most obvious manifestations of that," he said.
"The Royal Air Force remains hugely committed in that effort - there has been no diminution of that effort over the last few months.
"So we have been extraordinarily successful in dealing with that. More to do though, because it will morph into something different.
"If I look at the other end of the spectrum, then there are the state based threats, and Russia is becoming increasingly assertive, challenging international norms, putting pressure on us."
Air Chf Mshl Hillier said there are then a whole range of other conflicts in the middle of that spectrum to deal with and respond to.
"What the Royal Air Force has conclusively demonstrated with Iraq, Afghanistan, Libya, Iraq again, Syria now and even down to disaster relief in the Caribbean or protection of Nato flanks, is being sufficiently agile, flexible, multi role to operate across that entire spectrum.
"We are doing it well, and I need to make sure that we keep doing it well."