How long can a central bank continue an inflation? Probably as long as people are convinced that the government, sooner or later, but certainly not too late, will stop printing money and thereby stop decreasing the value of each unit of money. When people no longer believe this, when they realize that the government will go on and on without any intention of stopping, then they begin to understand that prices tomorrow will be higher than they are today. Then they begin buying at any price, causing prices to go up to such heights that the monetary system breaks down.
Just as the sound money policy of gold standard advocates went hand in hand with liberalism, free trade, capitalism and peace, so is inflationism part and parcel of imperialism, militarism, protectionism, statism and socialism.