I'm new to this - please forgive my ignorance

I assumed the Hague convention was the same for every country. A quick google reveals that Vietnam has not been accepted in the Hague convention club at least not by the UK ([url=http://www.adoptionintegrity.com/]Voices for Vietnam Adoption Integrity[/url]) - so what I want to know is if we adopt a Vietnamese child here in Hanoi (which is easy for locals such as my wife), then live here for a few years, if we go to England, are we no longer welcome there with our child?If not then surely the world's gone mad:(