The American secretary of state, Hillary Clinton, is attending meetings Hanoi and ahead of her arrival the US has called on Vietnam to release a number of activists which it says have been arrested or convicted unfairly. This week alone, nine people have faced legal proceedings for apparently having caused public disorder, including three labour activists jailed for up to nine years, and six Catholic parishioners. But while the US embassy has said it's 'concerned', American officials have economic interests with Vietnam that both sides will want to protect, so it's a fine line they are having to walk.