On the other hand it did not require much foresight to see that a system of scientific finance which was based purely upon selfish principles could not fail to lead to international complications. If every nation of Europe were to construct for its own advantage a hostile system of tariffs against other nations, excuses for war would be endlessly multiplied. However self-sufficient a country may be there must be many articles of convenience, if not of necessity, for which it depends upon its neighbours. Let a nation increase its colonial empire as much as possible, and keep its trade wholly to itself by an elaborate code of navigation laws, even then international trade will not die nor foreign smuggling be stopped. Protective duties and prohibitive legislation have never yet succeeded in destroying the commercial dependence of one civilised nation upon another. Nations which wish to protect their own trade by tariffs can only do so by constructing a system which shall be injurious to that of their neighbours, and is sure to lead to smuggling and reprisals. In the sixteenth century trade adventurers looked after themselves, and it was rare for the home government to consider itself compromised by high-handed acts of piracy committed by its subjects on the other side of the world. But when it was the action of governments themselves which led to collisions between their subjects, they were bound in honour to defend their own system. Tariff reprisals were instituted, and claims made of a right to punish foreign smugglers, and search foreign ships for smuggled goods, which were certain before long to lead to war in downright earnest. It has often been said that the wars of the sixteenth century were wars of religion, but those of the eighteenth century wars of tariffs. The Dutch war of 1672 is adduced as the first great war of the latter class, which was the first great war waged in Europe since the adoption of a scientific system of protective duties by a first-class power. There is some exaggeration in this statement, but it is undoubtedly true that, from the date of the adoption of a protective system by France under the guidance of Colbert, there is not an important war waged in Europe for a century and a half in which considerations of tariffs and commerce do not play a large part; and it may well be doubted whether the national organisation of finance any more than the national organisation of defence, though steps along the path of civilisation, have proved movements towards the attainment of peace. [Sidenote: =Contrast between Louis and Colbert.=]