Robert Higgs, long-time scholar of the links between warmaking and government growth (consult his classic Crisis and Leviathan early and often) has no qualms about reading anyone who supports U.S. military intervention abroad out of the libertarian movement. An excerpt:
My claim is that those who give a free hand to the government in its foreign and defense policy-making will ultimately discover that they have handed their rulers the key that opens all doors, including the doors that obstruct the government's invasion of our most cherished rights to life, liberty, and property. The war-making key is, so to speak, the master key for any government, because when critical tradeoffs must be made, war will override all other concerns….Anyone who has looked into the actions of the U.S. Supreme Court, for example, knows that during wartime the justices have placed themselves on the casualty list by effectively rolling over and playing dead. Without at least a semblance of the rule of law and an independent judiciary, all hopes for the maintenance of a free society are in vain.
An obvious response by hawkish libertarians appeals to an axiom of classical liberalism: we need the state to protect us from genuine foreign threats; moreover, provision of such protection is the state's most basic responsibility…..
[But] what makes anybody think that the state will protect us, as distinct from the state's leaders and its apparatus of rule? For more than a century, nearly all of the U.S. government's military activities have been devoted to protecting someone or something other than you and me (or, earlier, our forebears). Spain did not threaten Americans in 1898, and the Filipinos did not threaten them between 1899 and 1902. Germany did not seriously threaten any genuine American right in 1917–the right to travel unmolested in a war zone on munitions-laden British or French ships does not qualify, despite Woodrow Wilson's tortured logic–and the Kaiser's government made conciliatory efforts repeatedly to maintain peaceful relations with the United States from 1914 until 1917.
In more recent decades, North Korea, North Vietnam, Panama, Serbia, and Iraq, among others, did not threaten American rights before the U.S. government launched wars against them. If, in making war, the government intends only to protect Americans from foreigners who threaten their lives, liberties, and property here on our own territory, then we must conclude that the government has displayed astonishingly bad judgment in choosing its targets.