It's fascinating to see US senators blow their tops over the refusal of the former Justice Secretary, Jack Straw, and the Scottish Justice Minister Kenny MacAskill to appear before a Senate committee to answer questions over the Lockerbie affair.
It naturally prompts the question about whether any Westminster select committee at Westminster has ever got a US government official - or former official - to appear before them for a good grilling?
When asked today, the clerk of Commons committees couldn't think of any examples. The nearest similar case he could come up with is when several European MEPs appeared before a committee some years ago.
The former chairman of the Foreign Affairs Committee Mike Gapes, says his committee never tried to interview a US official during his time, and would never have dreamt of doing so. Not even during all the rows about the Iraq War.
"These senators are just grandstanding," Gapes told me.