Under Article IV of the Biological and Toxin Weapons Convention (BTWC) each State Party is required to 'take any necessary measures' to implement the treaty within its territory, under its jurisdiction or under its control anywhere. Such measures shall be taken in accordance with the State's constitutional processes.

This crucial treaty obligation remains poorly implemented, as has been repeatedly recognised by the States Parties. At the 5th Review Conference of the BTWC (2001-2002) they decided on a meeting of national experts (which was held in 2003) dedicated to the topic. In 2006, the final document of the 6th Review Conference recorded the decision that the first session of the annual work programme in the period between the 6th and 7th Review Conferences will return to this topic.

Meanwhile, the UN Security Council adopted Resolution 1540 in 2004, which makes the adoption of national legislative measures relating to the prohibition of biological, chemical and nuclear weapons mandatory upon all States, irrespective of whether they are party to the BTWC or not.

The EU Joint Action in support of the BTWC recognises the importance of national legislative measures in preventing inadvertent or deliberate contribution to the proliferation of biological weapons and materials, as well as of dual-use technologies that may contribute to their development, production and use, by both state and non-state actors.

The assistance the EU is offering to BTWC States Parties under the EU Joint Action is aimed to ensure the fulfillment of the obligation under Article IV of the convention.