The evidence does not support the claim that EU membership had taken away the UK’s ability to decide whether to sign extradition arrangements or go to war. On foreign and defence policy, the EU treaties required unanimity for CFSP decisions, and Article 31 explicitly says decisions under that chapter are taken unanimously, while military/defence decisions are excluded from qualified-majority voting; Article 42 likewise says any move to a common EU defence would require a unanimous European Council decision. The UK government also said in 2010 that defence remained a sovereign issue and that the UK retained an effective veto on any new EU CSDP activity. (eur-lex.europa.eu) On extradition and other justice-and-home-affairs measures, the UK had an opt-in protocol allowing it to decide case by case whether to participate in proposals under Title V, and the Home Office said in 2011 that the process allowed the UK to decide whether or not to opt in. That is a far cry from having simply given away the ability to choose. (gov.uk) Sources: EUR-Lex, Treaty on European Union Article 31; EUR-Lex, Treaty on European Union Article 42; GOV.UK, 2010 to 2015 government policy: international defence commitments; GOV.UK, Speech to the Institute of International and European Affairs; GOV.UK, European Arrest Warrant / JHA opt-in material.