I don't think there's any better blog-style discussion forum going, especially for foreign policy, than TPMCafe. To give just a small sampling of recent goodies:
Stephen Walt responds to the Princeton Project's FWLL.
Anatol Lieven on ethical realism.
Rachel Kleinfeld responds to Lieven and is subsequently schooled by Lieven.
Dan Drezner notes that it's a buyer's market in grand strategies, what with the wholesale failure of 43's foreign policy, and he takes on the FWLL.
Peter Trubowitz argues that, regardless of its merits, the FWLL could never generate bipartisan support.