They're very good; I've posted a few articles from them before. Basically a group of military and national security people writing on matters that are relevant to the United States. Search for "Bridge" on here, and you should be able to find most (if not all) of the posts I've made on here in regards to their stuff.
Ones I really like include "The Twilight between knowing and not knowing: US recognition of Genocide" (3 parts), "The passion of general James Longstreet", and "The Weaker Foe" (two parts).
This article was an interesting read, but (as with most sources) I'm cautious concerning bias inherent in 'The Bridge' basically being a bunch of military people.
Well, it is all military professionals speaking on military matters, so there's definitely going to be some bias from that perspective. When it comes to issues affecting political concerns and foreign relations bits, I think it's a very legitimate concern.
Where I think various authors really shine is on pure military matters. Take, for instance, this article on "multi-domain battle" (part 1 of 2). It basically shows how an enemy could fracture and completely disrupt normal US military operations if caught by a competent, innovative foe. It basically tells of a fictional battle where, for the first 24 hours or so, various elements of the US armed forces are completely cut-off from each other. Communication is spotty at best, and classic "Combined Arms" and "Airland Battle" doctrines that the US have been using since WW2 simply aren't working because sea, land, and air cannot coordinate, thanks to a powerful cyber warfare attack by the unnamed enemy. Admirals don't even know if they are at war, or if they should be supporting ground forces or not. For the first time, ground forces look up and realize that the US does not have control of the air.
It's a very plausible and telling scenario, and I think these kinds of articles, about how future wars will be fought, and other "pure" military issues (like ethics training for officers) are where they really show the site at its best.
Interesting, hadn't heard of this group before.