BBC Wales' Guto Thomas looks at the impact of Tony Blair's negotiations over the proposed European constitution on Wales.
Tony Blair is in Brussels for EU constitution talks
At the time of writing, just a few hours before Mr Blair and the other EU leaders arrive at the summit, there's a feeling in Brussels of the calm before the storm - except that there is no longer a guarantee that the predicted political storm is on the horizon at all.
That is because the path towards compromise may - at the very last moment - have been found by the Irish Presidency.
Late on Tuesday, the Irish Prime Minister Bertie Ahearn published a number of new proposals which may allow Tony Blair to agree to the draft constitutional treaty and also to maintain the UK Government's so-called red-lines.
With the summit meeting coming just one week after increasing numbers of Euro-sceptic voters went to the polls for the European Parliament, the domestic political pressure to reject the constitution has never been greater.
The Prime Minister has said he will resist this pressure.
Drawing our own Welsh red lines between the assembly, Westminster and the European Union is dangerously misleading and parochial
But the main challenge for Mr Blair is how to compromise on certain issues, without being seen to give away Britain's right to veto on key aspects of policy, such as foreign policy, taxation, social security payments to migrants, defence, the EU's budget, and criminal law.
The Irish answer to the problem is the concept of "emergency brakes".
This is - quite literally - the idea that if any member state feels that certain policies are travelling in the wrong direction, then it has the right to apply these brakes.
This is not a veto. It would not place a permanent blockage in front of a policy, but would, instead, divert it back for further discussion in the next European summit.
This mechanism could be enough for Mr Blair to argue that his "red lines" have not been breached.
However, the next hurdle is a major one.
Once a decision reaches the European Council, then the draft constitution no longer allows the absolute power of veto on many areas.
Instead, the latest proposal is that a "double" majority is needed, with the vote representing 65% of the EU's population, in at least 55% of the EU's member states.
The new constitution has arisen from EU expansion
That takes power away from the larger states - such as the UK.
And it may be a sticking point on specific issues, such as the UK Government's insistence that it will not accept any steps towards tax harmonisation across the European Union.
On a lighter note, there are also some relatively straightforward issues to sort out at this summit - the nominations for the new President of the European Commission (to replace Romano Prodi), as well as the new foreign policy chief.
The main challenge for Mr Blair is likely to be stop any arch-federalists from getting the presidency of the Commission - because such an outcome could further damage Mr Blair's credentials in advance of next year's UK General Election.
So what does this mean for Wales? Why should we be interested in these issues?
'Welsh red lines'
It's not as if they were linked to any areas of devolved powers or responsibilities?
The point is that drawing our own Welsh red lines between the assembly, Westminster and the European Union is dangerously misleading and parochial.
The issues covered by the draft constitution could dictate the way in which we are governed in the future.
In one way or another all these policies have a direct impact on everyone in Wales.
Legislation from the EU places clear limits on what government and people in Wales can and can not do - in agriculture, in our food, in consumer rights, in travel, in the work-place, in terms of our legal and human rights.
The list is endless.
And to influence those rules and regulations, so that they work for us rather than against us, then Wales needs to be fully educated about and effectively engaged with the process.