A little bit of history
It's funny that people are suggesting that Sweden is less likely to extradite Assange to the US than is the UK. The following text comes from a report found on the website of the European Court of Human Rights. Unfortunately it is no longer possible to provide confirmation of this, as the report in question was later removed from the website, some time between 16/12/2012 and 4/4/2013. The original link was https://hudoc.echr.coe.int/eng#{%22itemid%22:[%22001-115535%22]} .
"153. In short, the facts occurred in the following manner: on 18 December 2001,
Mr Agiza and Mr Alzery, Egyptian citizens seeking asylum in Sweden, were the
subject of a decision dismissing the asylum application and ordering their deportation
on grounds of security, taken in the framework of a special procedure at ministerial
level. In order to ensure that this decision could be executed that same day, the
Swedish authorities accepted an American offer to place at their disposal an aircraft
which enjoyed special over flight authorisations. Following their arrest by the
Swedish police, the two men were taken to Bromma Airport where they were
subjected, with Swedish agreement, to a 'security check' by hooded American agents.
154. The account of this 'check' is especially interesting, as it corresponds in detail
to the account given independently by other victims of 'rendition', including Mr El-
Masri. The procedure adopted by the American team, described in this case by the
Swedish police officers present at the scene, was evidently well rehearsed: the agents
communicated with each other by gestures, not words. Acting very quickly, the agents
cut Agiza's and Alzery's clothes off them using scissors, dressed them in tracksuits,
examined every bodily aperture and hair minutely, handcuffed them and shackled
their feet, and walked them to the aircraft barefoot."
Perhaps Julian Assange's concerns, and hence his behaviour, are more understandable in the light of the above?