One last comment (food for thoughts really): do study the history of the particular flight your looking for on the AMS-BRU-AMS. KL has a tendency to scrap the BRU connection quite often (see below - data points for the past 2 months), or at least more than other flights, and sometimes last minute (mine was cancelled 3 weeks ago while at the gate, waiting to board). Obviously, if the inbound AMS-BRU is cancelled, so will (in your current situation) your outbound, in which case I'm sure they'll figure out a way in AMS to scrap the AMS-BRU-AMS and have you directly on the AMS-US-bound flight.