Lazlo
Sorry, you are wrong to say when flying in Sweden, if the aircraft is British than you are operating to British limits not Swedish. The is no reason why the Swedish law should not apply to foreign aircraft. Indeed the Bill currently before the UK Parliament applies a 0.02 promille limit to the crew of all aircraft in the UK regardless of the registration of the aircraft or the nationality of the carrier.
Tandemrotor
The 0.02 promille limit has not be established by politicians but by the European safety regulators based on scientific evidence. I attended a Royal Aeronautical Society Conference on this subject a number of years ago and the consensus amongst the scientists making presentations was that the low limits were necessary.