Theatre Of Cruelty

Lets get this straight - an unknown agency poisons a man with a rare radioactive isotope, a highly dangerous one that probably could only be obtained through a government, smuggles it into Britain within the relatively short lifetime of isotope and uses it in central London; a material that could be attached to some form of dispersant such as a 'dirty bomb' - and this actual act of terrorism, by possibly a foreign power, doesn't cause a widespread terror alert?