<p>Of the schools you listed Johns Hopkins is definitely the superior school for IR, though i know nothing about St. Andrews. If you have a shot it Hopkins you certainly have one at Tufts, while Georgetown may be just one level up in terms of competitive admissions to their SFS. </p>
<p>JHU aside I'd have to say the Eliot School at GWU is your next best bet, purely do to its location. If you can afford it, it's a better school overall than American is. Syracuse in my opinion is to removed from the IR scene to really be considered a powerhouse in that field, though its still a very well respected institution.</p>