When Russia rained shells down on Georgia in August, it seemed initially as if Vladimir Putin was savagely pursuing Russian national interests. Moscow claimed Georgian aggression against Russian loyalists in South Ossetia and has objected to both Georgia's bid to join Nato and the Pentagon's arming and training of the Georgian military. But a closer examination of the run-up to Putin's inexcusable invasion suggests that Russia's action had as much to do with its wounded pride as with its alleged impaired security.

Thucydides long ago concluded that people go to war out of "honour, fear and interest". Putin seems to have chosen conflict largely out of honour, or, put another way, out of perceived humiliation – one of the most prevalent, least explored factors behind global violence.

Russia's litany of indignities dates to the early 1990s when the Soviet empire collapsed. A bipolar universe gave way to a world in which the "sole superpower" boasted about how it had "won" the Cold War. Russia was forced to swallow the news that Nato would grant membership to former client states in Eastern Europe, along with former Soviet republics. Russia, the fallen empire, would have to content itself with membership in the largely symbolic Partnership for Peace.

Perhaps the best example of Russians' brewing rage at their lost grandeur came in Kosovo, when, in the wake of Nato's 1999 war against Serbia – a war Russia opposed – Russian forces seized the airport that Nato had intended as headquarters for what many Russians considered an occupation force. No shots were fired, but western generals found it jarring to see how far Russia would go for a territory so marginal to its wealth and security.

When Western countries recognized Kosovo earlier this year, Russia's Nato ambassador, Dmitri Rogozin, telegraphed Moscow's plans by threatening to "proceed from the assumption that to be respected, we have to use brute military force". Putin said the "stick" that Western countries had employed "will come back to knock them on the head".

Russia is not alone in believing that amassing military strength or using violence helps restore self-respect and honour. Osama bin Laden has rallied young Muslims to his terrorist ranks by invoking Israel's occupation of Palestinian lands, America's military presence in Saudi Arabia, the US occupation of Iraq and the Muslim detainees degraded by their American guards. Ahmed Al Haznawi, one of the 9/11 hijackers, made a video before the attack in which he declared, "The time of humiliation is over".

On occasion, Western countries have consciously avoided humiliating militant powers, fearing the consequences of emasculation. Having neutered Germany following World War I, the Allies showed West Germany respect after World War II, investing heavily in its economy and absorbing the country into Nato. And while president George W Bush seemed unconcerned about Russia's simmering fury when he lobbied for Georgian and Ukrainian entry into Nato earlier this year, many European governments rejected the proposal, showing that they – perhaps because of their own history – were more attuned to the risks of compounding Russia's growing and alarming sense of victimhood.

Diplomats and intelligence professionals must acknowledge that honour and humiliation often weigh as heavily in the minds of statesmen and citizens as do economic and security interests.

Americans, who have not experienced a precipitous drop-off in power, have difficulty relating to the running tallies of slights maintained in other places. They must avoid the habit of projecting onto others their own ideas of what is rational. This is one more reason to expand the anthropological, historical and language training of diplomats and others.

This is not to suggest that the west do for Russia what the US did for Germany – integrate an aggressor. Invading a country out of humiliation is as deplorable as doing so for territory or riches. Indeed, the west must be prepared to sanction Putin for the invasion of Georgia. The US and its allies can avoid humiliating Russia by acknowledging that Georgia is not blameless and that the rights of Russian minorities must be protected. But western countries must refuse to accept Russia's cease-fire assurances without independent monitoring, and they must state that Russia's continued membership in the G-8 and future entry into the WTO will turn on its peaceful resolution of regional disputes. The upside of Russia's preoccupation with lost status is that its exclusion from such elite organisations would sting. Russia has flexed its resurgent muscles at great human cost. Now it must be convinced that aggression does not restore honour; it soils it.

Samantha Power is a Pulitzer Prize-winning author, Harvard University professor and foreign-policy analyst