Kentucky Senator (and presumptive Republican presidential candidate for 2016) Rand Paul last week raised eyebrows, hackles, chuckles, and (he undoubtedly hoped) his esteem as a serious foreign policy thinker when he said he'd like to see (Congressionally approved) military action against ISIS. Paul made sure, via Time, that everyone knew despite his noninterventionist reputation, he absolutely wanted airstrikes, arming of Kurds, and more help for Israel to boot.
Jon Healy at the Los Angeles Times did some concern-trolling recently for libertarians unhappy with Paul's recent pronouncements, calling them Paul's "biggest liability" as a politician. He singled out Reason's Jacob Sullum and Robby Soave, suggesting that critiques from thinkers or voters who might be otherwise Paul's biggest supporters makes for bad politics—if a libertarian wants Rand Paul to be a more successful national politician.
But there are (at least) three good reasons why even libertarians who wish Paul well as a national politician should not hesitate to criticize him over his ISIS declarations.