Prime Minister David Cameron and his cabinet colleagues have warned of a prolonged campaign to root out the Islamic State (Isis) from Syria, following the UK's first bombing raid on the terror outfit's strongholds in the region. They also stressed that a transitional government in Syria would help the global military campaign against the IS.

"We are going to need to be patient and persistent. This is going to take time. It is complex, it is difficult what we are asking our pilots to do, and our thoughts should be with them and their families," Cameron was quoted as saying by the Daily Mail.

Defence Secretary Michael Fallon warned that the military campaign "is not going to be quick" and could last for years rather than months. He told the BBC: "The American estimate of the campaign in Iraq, which began last year, was that it would last at least three years and we're not halfway through that yet."

"The operations there by the coalition have lasted just over a year and the prime minister has been pretty clear that this is going to be a long campaign to ensure that Daesh [Isis] are thrown out of Iraq and that they are degraded and defeated in eastern Syria. This is not going to be quick," he said.

Daesh – What's in a name?

Should we cease referring to the terrorist group that controls swathes of Iraq, Syria, Libya and Egypt's Sinai as Islamic State, Isis or Isil and begin using Daesh?

The term Daesh has become official terminology in Russia and France, where it was adopted as far back as September 2014, and has a major advantage in that IS fighters and leaders hate it. The word is an Arabic acronym of "al-Dawla al-Islamiya fi Iraq wa ash-Sham" – meaning the Islamic State of Iraq and al-Shams – but Daesh when spoken sounds similar to the Arabic words translating to "the sowers of discord" (Dahes) or "one who crushes underfoot" (Daes).

Due to Arabic wordplay, Daesh could be considered an insult. IS threatened "to cut the tongue of anyone who publicly used the acronym Daesh, instead of referring to the group by its full name". Muslims have always preferred to use the term Daesh rather than Islamic State, arguing the territory the group controls in Iraq and Syria is not a state, and its oppressive style of rule does not reflect Islamic values.

The first bombing raid by the UK on IS strongholdsin Syria was carried out by four RAF Tornado jets, which were seen taking off from the Akrotiri base in Cyprus early on 3 December. Two Tornados and six Typhoon fighter jets have joined the bombing raids, doubling the UK's strike capability against the IS. "This strikes a very real blow at the oil and the revenue on which the Daesh [Isis] terrorists depend," Fallon said.

"Overnight, RAF Tornado GR4s, supported by a Voyager air refuelling tanker and a Reaper, and operating in conjunction with other coalition aircraft, employed Paveway IV guided bombs to conduct strikes against six targets within the extensive oilfield at Omar, 35 miles inside Syria's eastern border with Iraq," the Ministry of Defence (MoD) said.

"The Omar oilfield is one of the largest and most important to Daesh's [Isis] financial operations, and represents over 10% of their potential income from oil. Carefully selected elements of the oilfield infrastructure were targeted, ensuring the strikes will have a significant impact on Daesh's ability to extract the oil to fund their terrorism," the MoD added.