If advocates of Britain remaining in the EU haven’t noticed, America’s international commitments are under attack from several populist directions in our ongoing presidential campaign. Some, especially among Democrats, simply do not value national security, preferring to focus on domestic issues, hoping – God forbid – to make America look more like social-democratic Europe. Others, especially among Republicans, think America’s allies have got a free ride, don’t appreciate US efforts, and should be made to fend for themselves. If Britain votes to stay In, this view may prevail across Washington. So be careful what you wish for.