While Iran keeps enriching uranium, Europeans achieved their objectives in their co-operation with the US: to increase sanctions in a multilateral framework and resolve the issue without military force.
In 2010, Europeans had successfully co-operated with Americans to take steps to put pressure on Tehran to respect its obligations under the Non-Proliferation Treaty, including through UNSC Resolution 1929. This was in line with their stated objectives and principles – to keep the process in the multilateral framework, to keep the international community united, to prevent American extra-territorial sanctions, and to leave the door open to serious negotiations with Iran. But these measures have not yet produced the desired result, as Iran is still enriching uranium.
In 2011, Europeans – especially the E3 (France, Germany and the UK) and Catherine Ashton – kept co-operating with the US to increase pressure on Tehran. For example, after the IAEA revealed the military intentions of the Iranian nuclear programme in its November report, they pushed other countries to adopt a more severe resolution at the IAEA board and increased their already-stringent sanctions on Iran in December. They were also vigilant against potential US sanctions on European firms participating in the exploitation of the Shah Deniz gas field in Azerbaijan since an Iranian company also takes part.
To some extent, Europeans have been more determined than the Obama administration on Iran – especially after rumours in the autumn of a possible Israeli attack, which they would consider a very dangerous development. After all, they had much more extensive economic relations with Iran than the US and the cost of sanctions for them has been much greater as a result. France also pushed for much more biting sanctions in November, including on oil exports and the Iranian central bank. Europeans are also more mobilised on the human rights issue than Americans, and imposed specific sanctions in April and October.