The relationship between war, taxes, and public opinion has long interested scholars of democracy and international security. In theory the fiscal costs of war should restrain leaders from starting them, especially if those costs are born by the public on whose support they rely. According to Sarah Kreps, however, American leaders have not been constrained in this way for decades. They have learned to find alternatives to the kind of war taxes that concentrate public attention. They have also fought prolonged wars with volunteer forces. No draft, no tax, no protest.