Nationalism can build democratic consensus or lead to war. But it is not the only cause of war. War is older than nationalism. ‘Good’, liberal nationalisms highlight democracy, the equality of all citizens before the law, a strong rule of law, tolerance and inclusion. They stress the accommodation of diversity through democratic consensus. ‘Bad’ nationalisms highlight the outdated concept of the “nation-state” and the alignment of territory with culture, religion or ethnicity. Such nationalisms are often authoritarian, illiberal and intolerant. They are also oblivious to the fact that most states have diverse populations, to ideas of liberal democracy, human rights upheld by the rule of law, the ideal of equality and consensus between different communities. They stress discrimination against ‘other’ communities and assimilation, sometimes even by force. Their intolerance and xenophobia can make them a threat to domestic stability and international peace. If the forces of intolerance are not defeated; if the rule of law is weak or continually hit and dented, bad nationalisms can emerge in democracies. International norms advocate the management of diversity through democracy, respect for human rights and tolerance. But they sometimes come into conflict with the sovereignty of states.