The second of these great causes of war, protection and the competition for markets, has somewhat changed its aspect since the comparative exhaustion of the world supplies of food and raw material. Before the war, nations chiefly wanted to sell. Markets were the great object of ambition, and tariff walls the great means of offence. Great Britain, of course, kept her doors everywhere open to the trade of the world. It is one of the decisive marks to her credit in the apportionment of the comparative guilt of the nations in preparing that international atmosphere which made the war of 1914 possible. But if she had chosen at any moment to close her doors, she could have injured grievously every other great nation throughout the globe; and the British Tariff Reform Campaign was one of the excuses used by the German Government to frighten their people into a war spirit. When Austria wished to ruin Serbia she simply put a prohibitive duty on the import of pigs. Now, since the war, what most nations want is not in the first place markets; it is food and raw materials. They have not, of course, abolished their tariffs, but their first anxiety is to be able to buy food. Austria does not want to keep out Serbian pigs. She begs for them, and Serbia will not let her have them. The most consistently and narrowly protectionist nations, like France or Australia, no longer concentrate on forbidding their neighbours to sell to them. On the contrary, they refuse to sell food and raw material to their neighbours. The policy of keeping the food and raw materials of the British Empire for British consumption is already widely advocated and has powerful champions in the Government. As long as it is confined to palm kernels, this policy, though bad from almost every point of view, is not fatal. But if ever it were to be carried consistently through, it would mean war. The British Empire holds such a vast extent of the earth's surface that it has inevitably given hostages to fortune. So huge an empire can only be tolerated if it behaves tolerably. If we keep to ourselves and use for our own profit all the overwhelmingly large stores of food and raw material which by our vast annexations of territory we now control, thereby reducing other nations first to a stagnation of trade and then to starvation, the natural and inevitable answer to such a proceeding would seem to be a world crusade for our destruction.