The British government's threat to invade the Ecuadorean embassy in London and seize Julian Assange is of historic significance. David Cameron, the former PR man to a television industry huckster and arms salesman to sheikdoms, is well placed to dishonour international conventions that have protected Britons in places of upheaval. Just as Tony Blair's invasion of Iraq led directly to the acts of terrorismin London on 7 July 2005, so Cameron and Foreign Secretary William Hague have compromised the safety of British representatives across the world.