Hi Karl. Unfortunately the US degree doesn't provide enough training to get registered in the UK. You could however take a masters in the UK and this could lead to recognition with the HPC. You post mentions Europe though and so there are different rules over there, and you might have better luck in Germany. There are a number of recruiters that advertise on PhysioBob's Jobs - Physiotherapy Job & Course vacancies, Physio Recruitment & Courses for physiotherapists for military physio jobs in Germany (with English speaking bases). As the legal structure in the military is different this might also be an avenue.
Best of luck