Being a US Citizen will certainly help you for obvious reasons.

You will still, however, have to go through the process of being licensed in whichever state you choose to work in. Part of this process involves your degree being credentialed by an independent company (each state has their own preferences so check with the state board). The credentialing process includes your university documents being forwarded directly from your educational instution to the credentialing company who will relay their recommendations to the state. You will also have to take and pass (of course) the board exam for the state that you're applying to. I would think that you would have to take the board exam in the state that you're applying to but in this day and age maybe you could take the exam in the Netherlands...

Medicare is now requiring that all foreign trained therapists have their degree credentialed by 2010. The credentialing process above should take care of that.

There may be other processes involved which I've missed but I believe this should be sufficient for your particular situation.

I would think that the APTA would be a great resource for you as well.

Good Luck!