Why is Libyan conflict less controversial than Iraq?
It was one of the defining moments of the last Labour government's years in power.
The Commons debate in March 2003 that preceded the Iraq invasion is seared in many people's memories.
Although Parliament authorised the decision to go to war, 122 Labour MPs defied the whip and voted against the Blair government while another 81 MPs from other parties joined them.
Fast forward eight years and when another prime minister asked MPs to approve military action abroad, they did so by an overwhelming majority.
Only one MP from the Conservative-Lib Dem coalition voted against the government's plan to deploy British planes in Libya while just another 14 MPs joined him in the No lobby.
In many ways, the difference between the build-up to the war in Iraq and the military action in Libya could not be more different.
In 2003, MPs approved an invasion of a sovereign country - many believing Tony Blair's case at the time that Saddam Hussein still possessed deadly weapons and was in a position to use them quickly unless checked.
The government's use of intelligence in the run up to war caused a divisive political row that only intensified when that intelligence proved to be wrong.
For the Labour Party in particular, the question of whether an MP voted for the Iraq war or not became a major factor in their chances of being re-elected and their future career prospects.
There has not been the same controversy over the motives for acting in Libya, while the UN mandate authorising allied action specifically ruled out "boots on the ground" - a land invasion - which also helped to lower the political temperature.
But as the UK's involvement in Libya has steadily intensified some MPs are asking why more parallels are not being drawn between the two conflicts.
For most Labour MPs the key difference between Iraq and Libya seems to be the stance of the UN and the mandate it gave the allies.
While the failure to get explicit UN approval over Iraq remains a source of contention to this day, UN resolution 1973, permitting the allies to use "all necessary means" to protect civilians in Libya short of an occupation, was passed unopposed - although five nations abstained.
"The UN's authority made the difference," says Kate Hoey, who opposed the Iraq war but backed the Libya action.
Richard Burden, another Iraq rebel who supported the Libyan intervention, says it should not be forgotten that the UK and other nations intervened on humanitarian grounds to prevent a feared massacre.
"I was against invading Iraq and believe I was right about that. But the situation in Libya is different," he argues. "As a result of the UN's action, Gaddafi could not carry through his threat to the people of Benghazi."
Libya was a "test" of the international community's willingess to act to stop mass killings on the scale seen in Bosnia and Rwanda during the 1990s, he says.
But he insists the west needs an "exit strategy" and must continue to argue for freedom of speech and the right to protest in countries like Syria and Bahrain in order not to be accused of double standards.
The apparent lack of opposition from MPs to the Libyan mission, when compared with Iraq, may simply be down to Parliamentary arithmetic.
Of the 122 Labour MPs who voted against committing UK troops in Iraq, more than 80 have since left the Commons.
As in 2003, the main opposition party is supporting the government and few of Labour's 2010 intake of MPs were likely to defy Ed Miliband less than a year into his leadership.
The complexion of British politics is clearly very different than eight years ago.
The Lib Dems - the only one of the three largest parties to vote as one against Iraq - are now in government and not looking to rock the boat on this issue.
Party discipline may also partly explain why only one Tory - John Baron - voted against the Libyan motion although a number of Conservatives who defied their party whip in 2003 have expressed reservations about how Parliament has been consulted and the timing of the original vote.
Although the pro-intervention coalition seems to be holding firm, the decision to deploy Apache attack helicopters in Libya - taken when Parliament was in recess - has raised fresh concerns about the extent of UK involvement and whether its policy is clearly now one of regime change.
Labour's deputy leader Harriet Harman has called it a "major escalation" and urged the UK to focus on the humanitarian situation.
Labour MP Barry Gardiner, who voted against the Libyan action, says he believes many MPs supported the intervention with a "heavy heart" at the time, because they were genuinely worried about what would happen if pro-Gaddafi forces entered the rebel stronghold of Benghazi.
But he also believes many did not look "sufficiently closely" at the terms of the UN resolution and its remit was "too wide".
"I think what has become increasingly clear is the fact that this was never simply an intervention for humanitarian protection. What is increasingly clear is that the UK and Nato have taken one side in a civil war," he says.
"I just think we were wrong on this. I appreciate that many colleagues were concerned about the immediate humanitarian situation and felt, in that situation, that they had no alternative but to support the government. My view was that there was an alternative way."
Amid growing unease about Nato's role, MPs are expected to press for a statement on Libya on Tuesday when Parliament returns from its 10-day recess.
Although he voted for the Iraq invasion in 2003, Mr Gardiner says the parallels between the two situations are "ironic".
"Every single argument that has been used over the last eight years to decry what happened in Iraq is being used to justify - with much less justification - what is going on in Libya," he argues.
Despite the frequent military interventions of the Blair years, he believes Labour should be looking further back into its history for its foreign policy principles.
"There is a historic role for Labour that is not being followed through here - as effectively an anti-war party that recognises war is the worst option and something that should be avoided becoming embroiled in at all costs."
And while in no doubt about the nature of the Gaddafi regime, he worries that the current intervention sets a worrying precedent for the future.
"The danger is we are being drawn into a position, in terms of what we should be doing internationally, of it 'does not matter because it is only Gaddafi'."