After the calamitous wars of late Eighteenth Century the five major powers of Europe, Britain, France,
Germany Prussia, Austria and Russia reached a sort of accord in the Treaty of Final Act of the Congress of Vienna of 1815. They would cooperate to prevent future continental wars and not have their foreign trade interfered with. Moreover, after 1815, a creeping generic liberalism spread over the continent. Naturally the treaty was not completely successful, and wars continued, but not on the scale of the religious, dynastic and Napoleonic wars of earlier times. Nor was the advance of liberalism especially rapid or steady.
So what were the tenets of this mid-Nineteenth century liberalism. According to Constant:
Modern societies, he suggested, were too complex to be ruled politically after the fashion of an ancient city state – the model to which many earlier writers (including Rousseau) had appealed. Diversity, pluralism and localism were the secret of stability and freedom. Secondly, the legislators, to whom the executive should answer, should be drawn from those least likely to favour the extension of arbitrary power or to be seduced by a demagogue. Politics should be the preserve of the propertied, who would exert a wholesome (and educated) influence on the ‘labouring poor’. The propertied were the true guardians of the public interest. Thirdly, it was necessary for property rights and other civil freedoms to be protected by well-established rules – an ideal that implied the codification of the law and its machinery.9
Darwin, John (2010-08-08). After Tamerlane (pp. 229-230). Bloomsbury Publishing Plc. Kindle Edition.
In the short run, at least, this liberalism was a help rather than a hindrance to European imperialism. The rest of the globe would now be subjugated, not in the name of one or the other of a bunch of religions that didn't impress them, but in the name of giving them the blessings of liberal value.
Unlike previous ideologies espoused by European expansionists – crusading imperialism, mercantilism, dynastic absolutism – generic liberalism proved remarkably attractive to some at least of the colonized. Its values were, or seemed, universal: they appealed to Indian, Chinese, African and Arab elites almost as much as to Europeans. Here was an astonishing and unprecedented third dimension to the expansive powers of the Europeans. It endowed them (that is, the more skilful practitioners of ideological politics) with a flexible new weapon in the search for allies in the non-Western world. It helped to prise open societies closed to all their other threats and blandishments. It was – or later seemed to its embittered foes – the Trojan Horse of European imperialism.
Darwin, John (2010-08-08). After Tamerlane (p. 237). Bloomsbury Publishing Plc. Kindle Edition.
In the end, liberalism, or a form of it, would become one of the most powerful weapons of the anti-colonialists. Ultimately liberalism, at least in the modern conception, was not compatible with alien rule of subject peoples. Though hardly the only factor, this liberalism claimed as one of its first accomplishments the gradual abolition of one of the nastiest aspects of European colonialism - the African slave trade.