Many journalists have contacted me on the issue whether Julian Assange can be extradited to the US via Sweden for espionage where he might face the death penalty. The short answer is: no. Below you will find the long answer.
How does procedure work if somebody is to extradited from Sweden? Pursuant to section 14 of the extradition of criminal offences act a "request for extradition shall be made in writing. It may be transmitted by telefax or, subject to agreement in the individual case, by other means. The request shall be made to the Ministry of Justice." The request shall according to section 15 of the same act be rejected immediately if there is a manifest reason why it should not be granted. Otherwise, the request is forwarded to the office of the Prosecutor-General who shall deliver a statement of opinion on the matter. In addition, if the person referred to in the request has not consented to being extradited, the case shall be tried by the Supreme Court. Section 20(1) provides that if the Supreme Court has considered that there is a legal obstacle to extradition the request may not be granted. Even if the Supreme court has found that there are no obstacles, the Government can refuse extradition. This is because section 1(1) provides that if certain conditions are fulfilled, a person "may" not "shall" be extradited. In other words, even if the Prosecutor-General and the Supreme Court finds that all conditions for extradition are fulfilled the Government may veto such extradition. It does not work in the reverse way, the Government can not grant extradition if the Supreme Court has found that any of the required conditions are lacking.
As I understand, Assange wants the Swedish Government to guarantee that it will not grant extradition to the US. The US has not made any request to the Sweden on this matter. In other words, Assange wants the Swedish Government to pledge to use its veto power in relation to a non-existing request and before the Prosecutor-General and the Supreme Court has evaluated this non-existing request. There is nothing in the extradition of criminal offences act that deals with this scenario, but it would depart from established practice. Cameron and et. al write in a general way about this in their book "International Criminal Law from a Swedish Perspective", Intersentia, 2011, p. 171.
Assange fears that he will be extradited to the US where he may be at danger of being for torture or receiving the death penalty. There are at least three obstacles that makes it difficult or even impossible to extradite Assange to the US.
First, Sweden (as the UK) is party to the European Convention of Human Rights. The convention has been incorporated in Swedish law which makes it directly applicable for all state agencies, courts and the Government. Following the Soering Case, Sweden (and the UK) are prohibited from extraditing a person who may face the death penalty. Subject to are obligations from European Convention of Human and the Convention against Torture there is also a prohibition from extraditing somebody where there are substantial grounds for believing that he or she would be in danger of being subjected to torture (which includes inhuman or degrading treatment or punishment).
Second, pursuant to article 28(4) of the Council Framework Decision of 13 June 2002 on the European arrest warrant and the surrender procedures between Member States "a person who has been surrendered pursuant to a European arrest warrant shall not be extradited to a third State without the consent of the competent authority of the Member State which surrendered the person. Such consent shall be given in accordance with the Conventions by which that Member State is bound, as well as with its domestic law." Cameron and et. al write the following on p. 191: "It can be noted here, in connection with the EAW proceedings in 2010 concerning 'Wikileaks' founder Julian Assange, that the principle of speciality means that Assange cannot be extradited or deported from Sweden, unless the UK grants its permission for this." This means that the present decision from British authorities, upheld by Supreme Court, to extradite Assange to Sweden for sexuually related crimes is not enough. If the US would request Sweden to extradite Assange the issue not only have to be approved by the Prosecutor-General, Supreme Court and Government in Sweden, it also has to go through the British legal system a second time (which took more than 500 days the first time). In other words, if the US wants Assange extradited from Sweden he will have the protection of both the Swedish and British legal systems. It would appear easier to have him extradited directly from the UK.
Third, the Swedish extradition agreements with the US does not allow extradition when the offence is purely military or if the offence is a political offence. See article 5(4)-(5) of Convention on extradition between the United States of America and Sweden, 24 October 1961. See also the supplementary convention from 14 March 1983. Cameron and et. al write the following on p. 177: "No definition is given in the Extradition Act of what offence constitute a political offence. In Swedish extradition law, as in many other countries' extradition laws, a distinction is made between absolute and relative political crimes. Absolute political crimes are those exclusively directed against the state... espionage is an absolute political crime according to the travaux préparatoires". One may add that in Swedish law, as opposed to English law, travaux préparatoires is as source of law.
As I understand Ecuador has granted Assange political asylum, i.e. Ecuador is arguing that the US is seeking Assange for a political offence (espionage). Moreover, they fear that Assange will be subject to the death penalty and/or torture. As explained above, extradition from Sweden would for several reasons not be granted in such a case.
It is theoretically possible that i) the US might charge Assange for an other (non-political) crime than espionage and that ii) the US would be willing to issue a guarantee that the death penalty will not be issued. The latter has happened before - see for example the aftermath of the Soering case. Could Sweden extradite Assange in such a case? The answer is yes provided that the UK also approves, but I have great difficulties to see what kind of non-political crime that would be. We can of course discuss all kind of theoretical cases which I do all the time with my students at the University. The question is if sovereign states such as the UK, Sweden and Ecuador should take action on such theoretical cases, regardless of their likelihood and basis in reality?
Update 1. Pål Wrange has written two excellent blog posts in Swedish on, inter alia, the “temporary surrender”-procedure in the Swedish-US extradition treaty which has caught some attention. Some argue that it can be used to circumvent all the requirements that I describe above. Wrange makes two conclusions that are notable. First, the "temporary surrender" procedure has to fulfil the same conditions as the regular surrender procedure. Second, the same "temporary surrender"-procedure exists in article 14 of the British-US extradition treaty.
Update 2. Above I write that Assange "will have the protection of both the Swedish and British legal systems" if there is a extradition request from the US. In the comments to this blog post there is a discussion whether this includes an additional judicial review in British courts. As I understand an additional decision to extradite a person to a third country (the US) following a surrender under the EAW is taken by the UK Home Secretary. There is nothing in UK law which explicitly state that this decision is subject to judicial review. Therefore I would like to adjust my statement above. It would have been more accurate to state that any extradition request from the US have to be approved by both the UK and Sweden. As explained above, the Swedish Supreme Court needs to approve such requests while the precise procedure in the UK is unknown for me.