Should UK Go To War In Syria? Pros And Cons

As MPs prepare to debate the reasons for and against airstrikes in Syria Sky's Robert Nisbet examines the arguments.

:: Arguments against airstrikes in Syria:

1. The danger that despite efforts to target military positions, Syrian civilians could be killed.

They have already suffered through years of a complex and bloody conflict, could an extension of military activity endanger their lives still further?

2. There's scepticism that the allies would be able to muster the required troops to fill the vacuum, if airstrikes manage to degrade IS in Raqqa.

The Prime Minister says his "experts" have identified 70,000 potential pairs of boots on the ground assembled from moderate opposition fighters, such as the Free Syrian Army, but will they materialise?

3. Are we sowing even more confusion in an already complex battle between competing religions and regional interests?

The United Kingdom has already expressed its determination to rid Syria of the brutal regime of Bashar al Assad, but by hobbling Islamic State, one of his main enemies, would we help him to cling on?

4. France and the US are already bombing Islamic State positions in Syria and although the group is thought to have lost a third of its territory, the extremists are still able to orchestrate or inspire attacks both across Syria and in the West.

Would our contribution change that?

5. Would airstrikes create more homegrown jihadis in revenge for our participation?

The counter argument is that airstrikes are helping Islamic State's international recruitment drive.

6. The spectre of the Iraq War looms large for many opponents.

Does the recent UN resolution 2249 - which gave backing for "all necessary measures" to eradicate IS safe havens - constitute legal backing for airstrikes?

:: Arguments for airstrikes in Syria

1. After terrorist attacks at home and abroad, the UK needs to show solidarity with NATO members which are already staging airstrikes in Syria.

2. It's strategically inconsistent to target IS positions in Iraq - where the UK is already engaged - but not in Syria.

They don't recognise the boundary so why should we?

Also we have used drones to target individuals who are deemed to represent a threat to Great Britain and are already providing pilot assistance in Syria, so this is the logical next step.

3. Airstrikes could help destroy the infrastructure which is keeping Islamic State awash in cash, which helps the organisation attract volunteers and finance terrorist attacks.

4. The United Nations voted for a resolution which has called on the world to take "all necessary measures" to destroy Islamic State safe havens, so surely that constitutes a legal basis for extending airstrikes to Syria?

5. The British Government has made it clear that the UK faces a real threat from Islamic State inspired terrorism, with seven plots foiled in the last 12 months.

Can we just rely on intelligence to foil these attempts, or should we try to deal with them at source?

6. There is little doubt that IS poses a threat to peace and security in the entire region.

Although the situation is complicated with a mosaic of national interests at play, cutting off the "head of the snake" could help restore some stability in both Iraq and Syria.

:: What persuaded PM to seek second Syria vote?

:: Watch coverage of the Syria airstrikes debate and vote in the House of Commons live on Sky News throughout the day on Wednesday.