There are other parts to the action. One is Hussein’s trip to Pakistan in 1981, apparently on an Indonesian passport. If so then I believe he had to formally renounce his American citizenship to get that passport. That renunciation is recognized by the United States. Unless he later took an oath of loyalty in front of an appropriate American official he would not be a US citizen.
That wouldn't necessarily be true.There was a time (not all that long ago) when it was relatively easy to lose ones US citizenship.However,in the last 50 years or so the Federal courts have handed down a number of rulings which have resulted in it becoming very *difficult* to lose one's US citizenship.Unless he renounced his citizenship *before a US State Department official* that renunciation wouldn't be valid...wouldn't be recognized.Check the State Dept website for details.