Whether or not to commit our country to military action is the most grave decision any prime minister can make. When excitable defence correspondents on television talk about military 'assets' and 'capabilities', it is important to remember that what we are really talking about is somebody's son or husband, their dad, their brother, their partner, their friend.
That is why any decision to put the brave men and women of our armed forces potentially in harm's way must be preceded by the most careful of considerations and at all times a calm, patient and cool-headed determination to exhaust every option and to think through every possible implication. As Ed Miliband wrote this weekend in the Guardian:
"When it comes to questions of war and peace, the British people rightly expect that the seriousness of our deliberations matches the gravity of the decisions we are asked to take."
I listened very carefully to David Cameron in the House of Commons on Thursday as he outlined his position on Syria. It was not a moment for politics or the pantomime that normally accompanies occasions like Prime Minister's Questions. And in fairness, many Conservative and Lib Dem MPs also listened intently to Ed Miliband when he made his response to the Prime Minister.
But as Miliband outlined his view that there needed to be a proper international process at the United Nations that was evidence-led, and as he argued powerfully that we needed the "time and space" to come to a judgement and that we shouldn't rush headlong into a political timetable that was being driven elsewhere, one or two sillier Tory MPs, including ministers, regrettably, chose to heckle him with the word "weak".
The events of recent days have indeed shed some light on the contrasting leadership styles of David Cameron and Ed Miliband. The truth is David Cameron lost the vote last Thursday because of a failure of his leadership. Many MPs, on all sides of the House of Commons, felt that the prime minister's rather gung-ho approach meant that the UK was rushing headlong into the civil war in Syria without fully thinking through the alternatives or the wider consequences of military intervention.
It was obvious on Thursday, and from the good faith discussions that had taken place between the opposition and the government in the preceding days, that the prime minister had simply not done the work in terms of outlining a proper process or setting out a compelling case for military action.
This is something that troubled even senior figures in Mr Cameron's own party. The former Conservative foreign secretary Douglas Hurd told the House of Lords that he was "not persuaded that the government have made a case for the action that they propose".
Norman Tebbit was right when he wrote last week that the vote in the Commons was "an expression of a lack of confidence in the ability or willingness of the government to think through the consequences of its policies over a far wider front than Syria".
And the Conservative MP David Davis put it bluntly the day after the vote when he said:
"I am not an anti-interventionist but interventions have to have a clear purpose, have a decent chance of succeeding, and you have to be able to calculate that the risks of it all going wrong are. None of these criteria were met yesterday."
As someone who worked at the Ministry of Defence at the time of the Iraq war, I know only too well that what defined the disaster that became the Iraq war was not just the monumental failure of intelligence or the catastrophe that was the post-war effort. The other big lesson from Iraq 10 years ago is that unless you have a proper, credible process in place leading up to any decision for military action, you will destroy any public confidence and trust.
On Syria this week, Cameron failed to outline a proper international process, he failed to set out the conditions that would need to be met for action to take place, and he failed to make a robust case that reassured people that military action would not make things potentially even worse for the Syrian people. Because of that, he failed to take people with him and to convince the public.
Add to that, in the 24 hours leading up to the crucial Commons vote, Cameron and his aides seemed to proceed in the most cavalier and reckless fashion. Infantile and irresponsible briefings from the prime minister's office combined with a complete organisational and political shambles at Downing Street. If David Cameron has a leadership crisis today, then it is one entirely of his own making.
The British public rightly remain deeply concerned about the chemical weapons attacks in Syria. The House of Commons was united in its horror and revulsion at the shocking images of badly burnt men, women and children gasping for breath in the fallout of the chemical attack. But our desperate desire to help stop the suffering in Syria that, even aside from the chemical attacks, has claimed the lives of at least 100,000 people, wounded another 200,000 and displaced more than four million, cannot lead us to make rushed or wrong decisions.
Labour's shadow foreign secretary Douglas Alexander set out very clearly in Saturday's Telegraph the urgent leadership role the British government must take to seek a renewed diplomatic, political and humanitarian effort, starting this week when world leaders from the G20 meet in St Petersburg. David Cameron now needs to step up to the plate.
Cameron's defeat in parliament last week should give him the opportunity to reflect on the kind of leadership Britain needs when it comes to Syria. Not impulsive or reckless and cavalier, but calm, measured and considered leadership acting at all times in the national and global best interest. It is about building alliances and having influence. It is about recognising that having the courage to pull back from the brink, to listen to the public and to learn the lessons of history, as Ed Miliband did last week, is actually to demonstrate strong not weak leadership.
Now all the focus of the prime minister and the government in the coming days needs to be in working with our allies to bring the appalling situation in Syria to an end with peaceful means.