My colleague Geoffrey Taunton-Collins argues that nationalism is a force for good, as the loyalty and fellow-feeling it generates are necessary to create high trust law-abiding societies. He says that examples of atrocities committed partially in the name of nationalism—the Rwandan genocide, the second world war and Holocaust, strife in the middle east—are all better explained by ethnic tribalism or religion. I disagree. Firstly I'm sceptical that successful modern societies are driven by nationalism, secondly I think it's impossible to disentangle the nationalist element in many of the terrible occurrences he lists, and thirdly I think that nationalism underlies some very bad policies adopted by many modern societies.

Why does an individual obey the law? One obvious reason is that the penalties for disobedience, weighted by the likeliness of their being incurred, often outweigh the benefits from breaking the law. A second reason, is that individuals believe there is some sort of justice in the laws. This is why people give "because it is against the law" as a reason independent of any further explanation for why a course of action ought not to be followed. Anecdotally, the arguments people give for the duty to obey the law—if these can be taken as also being the reasons they actually do obey the law—seem to go against Geoff's claim, centring on reciprocity, universality and fairness. And the cases where people disobey the law appear to go with my analysis. Consider illegal downloading: some estimates say PC games are illegally downloaded as many as 20 times as they are bought legally. People seem unswayed by the laws—brought about by the authority of the nation state they are supposedly loyal to—requiring them to buy games (or films, television programmes, music) legally. Because others are not following the law, and because the likelihood of punishment is low, they don't themselves.

Can nationalism and ethnic strife be disentangled? Certainly Hitler's regime looked no more favourably on the many proudly German Jews who had served the Kaiser honourably in the first world war than they did on any with Jewish ancestry. And certainly Nazism was centred on the idea of a Volk—a people—united despite the borders of Weimar Germany. But the purest form of an ideology is rarely what gets through and propagates throughout society, and the Dolchstosslegende—the idea that Germany didn't really lose the first world war, but was stabbed in the back by a Jewish-Bolshevik conspiracy—was a vital part of the Nazis' appeal. I think the general bleeding of racialist, ethnic and religious ideas into nationalism and national identity is inevitably tied into Middle Eastern conflicts and the two major central African genocides.

And finally, look at the policies nationalism produces. True, as Geoff points out, there is no necessary reason why nationalism should exclude anyone born outside the country, if they are willing to switch their loyalty to their destination nation, but in practice we know that's what happens. Taking the UK as an example, the tide of anti-immigration feeling has been rising and rising since Gordon Brown's 2007 pledge to provide "British jobs for British workers", culminating in the rise of UKIP and Tory policies like the 99,999 or less net inward migration pledge. Surely it can't be denied that a sense of nationalism, that the UK is collectively owned by only its current inhabitants, a sense of insider and outsider, is intimately connected to this ethically indefensible and economically incompetent trend?

As far as I can tell, actually-existing nationalism is not responsible for our generally law-abiding society, cannot be disentangled from many gross moral horrors, and is responsible for bad policy. Therefore I conclude that nationalism is a force for bad.