The clause was originally part of the EU's now-stalled draft constitution.
The clause says all member states will have to use all instruments at their disposal -- including military force -- to prevent terrorist attacks on other member states, or help them cope with the effects of an attack.
Irish Prime Minister Bertie Ahern -- speaking for the EU's current presidency -- explained that when the clause is invoked, each member state “will choose the most appropriate means to comply with this solidarity commitment towards the affected states.”
However, the clause also says each member state is free to decide what assistance to provide.
The EU yesterday also decided to appoint its first counterterrorism coordinator to oversee the pooling of some of the member states' intelligence resources. The position will be taken up next week by a senior Dutch civil servant, Gijs de Vries.
The counterterrorism head will report to the EU's security policy chief, Javier Solana. Solana last night said the official will coordinate the EU's antiterrorist efforts, and will also play a key role in ensuring member states put into practice the measures they've agreed to.
"At this point in time we think that what is most important now is to get better coordination in the different bodies that we have in the [EU] Council [of Ministers] already," he said. "They have to work better, and more efficiently and more rapidly. Second, to try to do, as I said before, better cooperation with the member states so that when [a] decision is taken, [it] is implemented by the member states. So there [has] to be somebody [who] is always following up [to make sure] that everybody complies with agreements [they] have taken, with the decision that [has been] taken. If they have to pass it through the parliament, [they] do it rapidly. If they have to agree it in the government, [they] do it rapidly."
Solana said the official will also liaise with non-EU countries on terrorism issues. He also indicated the EU will develop certain analytical and "operational" structures to assess intelligence acquired from member states and possibly act on it. However, Irish Prime Minister Ahern bluntly ruled out the possibility that the new body could become a budding European version of the U.S. Central Intelligence Agency.
The EU has already agreed to a whole raft of measures, such as a joint arrest warrant, joint investigation teams, common action against money laundering, and others. However, their implementation has progressed slowly. Last night, EU leaders committed their countries to putting all measures into practice by June this year.
Yesterday's declaration has already come under fire from civil-rights groups for paving the way for the long-term retention of phone records, as well as data relating to text messages and e-mails.
An important part of the new EU initiative is the tightening of its external borders. Databases are also envisaged which will retain information on non-EU travelers such as their visa details, photos, and, possibly, fingerprints, iris scans, and even DNA samples.
In parallel, Ahern said last night, the EU will make combating terrorism a key condition in its relations with other countries.
"The whole principle is that the message has to go out -- if you want good relationships from the regions of the world with the European Union, then you must build up -- and the European Union will help you -- your counterterrorism capacity, so that we're all clear that there is not any kind of toleration of anything that is not tough action against terrorism."
Ahern said the EU would not discriminate against immigrants or minorities in its attempts to eradicate the domestic elements of Islamic terrorism. He said human rights and the rule of law "will have to be complied with fully."
Romano Prodi, the president of the European Commission, yesterday sidestepped a question about whether the EU can guarantee that tighter counterterrorist cooperation with Mediterranean countries does not lead to new human-rights violations there.
French President Jacques Chirac, speaking alongside Ahern, pointed to the need to continue looking beyond terrorist acts to the social ills that breed them, particularly poverty: "The international community should resolve the conflicts which are the potential sources of terrorism. Of course, there are feelings of humiliation and situations of poverty which aren't addressed properly by the international community. So we have to examine the conditions that can improve situations which can otherwise serve terrorism."
Chirac said terrorism will not be eradicated unless the EU takes "clear and coordinated action to do all we can to destroy the roots of this evil."