Bet they wish they hadn't now. But it seems that while Lewd Rubbers was running Economic affairs, the father of Pakistan's nuclear programme, and by dint of his extra-curricular activities father of nuclear proliferation Kahn was arrested for espionage while working at "a centrifuge plant operated by Urenco" in 1975. Charges were dropped on US advice. Lubbers has gone on to point out that when he later became PM Khan was convicted in absentia, with the charge being overturned via a legal technicality. Again the US advised against further action.
I guess the truth about this could be discovered by efficient usage of the Freedom of Information legislation in the States.