In his Guardian column today, Simon Jenkins adopts a monocausal theory of war: war is caused by military expenditure. It's hard not to go some part of the way with this, since if there were no military expenditure people would have difficulty fighting one another. But that armies, navies and other warfighting resources cost money shouldn't prevent us from noticing that there are also non-monetary factors at work in bringing war about.
Thus, for example, when in his first paragraph Jenkins wonders why, since 'Britain's borders and British people have not been under serious threat for a generation', our leaders still take the country to war, he seems to imply that only threats of that nature and magnitude could justifiably account for war. Well, in 2001 after 9/11 the borders of the US weren't under serious threat and nor was the American people, since as wise birds often point out, more people died by falling into their fishponds or tripping on a carpet than were murdered on 9/11. And yet America was entitled under the laws of war to strike at Afghanistan, playing host at the time to the Al-Qaida perpetrators.
Then, in his second paragraph, Jenkins disparages military intervention for humanitarian purposes by treating it as merely a form of macho posturing. But this wouldn't necessarily be the way the victims of genocide or crimes against humanity on a mass scale viewed matters.
Most generally, with the aphorism that 'the devil makes work for idle hands' and that's why war occurs - because if we have the instrument we must use it - Jenkins appears to overlook the prior rationale for having instruments of any kind: namely, that their use may be imposed on you for reasons outside the existence of the instrument itself. You could want a hammer because something broke and it needed fixing; not so much because you'd done a sort of Charlie Chaplin and just had to go around hammering in nails. Jenkins seems impervious to the possibility that if 'we' all stopped spending on military resources, there might be other people who wouldn't. What a soft world he lives in.