By Paul Reynolds BBC News Online world affairs correspondent

Under the proposed EU Constitution, the foreign and defence policy of each member state will ultimately remain in the hands of its national government.

The constitution goes too far for some, and falls short for others

Each government will be able to veto any common policy with which it does not agree.

However, the pressure will be on even more than now to reach a common position. This is because the constitution does not just preserve national rights - it allows for future moves towards joint positions.

The national veto is preserved because there will be a common foreign policy only when the member states agree, as happens now. Governments will have to support such policies "loyally" which is the case at present.

An example of a common policy is the Israeli-Palestinian issue. The EU has a common position on supporting the road map which is supposed to lead to negotiations.

Disagreements

When even one state says no, there will not be a common policy, as also happens now.

QUICK GUIDE The EU constitution

An example of disagreement is the war in Iraq. Member states have expressed disagreements and there is no common policy.

But that is not the end of the story. Three mechanisms are proposed to allow for groups of countries to go further together.

The first is called "enhanced cooperation". This would apply across all EU policies, but in the foreign affairs and defence fields it could be done only by agreement from everyone.

KEY DEVELOPMENTS February 2002: Convention starts work June 2003: Draft submitted to EU Thessaloniki summit December 2003: Brussels summit fails to agree final text May 2004: EU enlarges to 25 June 2004: Text agreed Constitution full text (1MB)

The second would allow a state or states to abstain on an issue, allowing the others to go ahead and declare a common policy. If however, a third of the member states representing at least a third of the population abstained, the policy would be blocked.

The third allows for a majority vote on implementing certain agreed policies. In such a case a country wanting to use its veto for a vital national reason could do so, but it might have to have the issue discussed by heads of state and government first.

It is such mechanisms that make EU decision-making so complex.

There will also be a new EU foreign minister. This post will combine the current roles of the EU's "high representative" and the external affairs commissioner, so he or she will be a more prominent figure. The minister will speak for the EU, but only when there is a common position.

Power of the veto

The minister will be supported by an expanded EU "diplomatic service," which will be based on existing Commission representatives around the world.

Protection for national decision-making was pushed very strongly by the UK government, for one. It states with satisfaction in a White Paper on the constitution: "When we don't agree, there is no common policy."

The new EU will have difficulty finding a single voice

Indeed, the continuation of the veto has disappointed some countries, including France and Germany among the larger states and also smaller members like Belgium, who want greater integration - code for majority voting - in foreign affairs.

It should be recognised incidentally that trade policy, which long ago used to be a major factor in foreign policy, will remain under EU control and subject to majority voting.

And there will continue to be a common policy on development aid, though states will continue to have their individual aid programmes as well.

Common defence policy?

The constitution also allows for a common defence policy one day, though that would be the subject of future decisions.

Even more than in foreign policy, defence will remain for the time being in the hands of individual governments.

The commitment of most of the member states to Nato is recognised. So is the neutrality of others and a clause about mutual support is little more than the expression of the current position under the UN Charter.

But as in foreign policy, a way is cleared for future joint action by agreement. The constitution says that there could be joint EU action in "peacekeeping, conflict prevention and strengthening international security" - terms which cover just about anything. Decisions would have to be taken by unanimity.

The EU took its first modest step into peacekeeping when it sent a police unit under a Danish commander to Bosnia to take over from the UN in 2003.

There would also be a largely undefined process called "permanent structured cooperation." This would enable willing member states to group together more closely over defence.

This is seen by some as an embryonic common EU defence policy.