Before the Brussels summit fell apart in December, EU leaders reached agreement on one of the most sensitive aspects of Europe's future - its security and defence policy.
They accepted a compromise agreed between France, Germany and Britain that will create a small military planning unit to co-ordinate EU operations that are mounted without the help of NATO and adopted a security strategy that identifies key threats and outlines steps the EU should take to address them.
The Irish presidency will begin the process of establishing the military planning unit, which will only employ a few dozen officers but has raised fears in Washington that the EU could be creating a parallel defence structure to NATO.
The presidency will also take the first steps towards creating an intergovernmental agency for defence capabilities development. The agency, which will probably be based in Brussels, would allow member-states to work together on a voluntary basis to enhance their forces' capacity to work together and to reduce unnecessary duplication.
The Government is understood to be interested in the possibility of Ireland working within the agency with Nordic countries that share a similar defence and foreign policy tradition.
EU police missions in Bosnia and the Former Yugoslav Republic of Macedonia will continue during the Irish presidency and preparation will begin for the biggest EU military operation to date - a follow-up to SFOR, the NATO-led peacekeeping mission in Bosnia-Herzegovina.
At its height, the Bosnia force had a strength of more than 50,000 soldiers, a number that has now been reduced to 12,000. By the time the EU takes over the operation at the end of this year, the number of troops will have fallen to 7,000, which is expected to include members of the Irish defence forces.
Irish officials believe that the EU will have no difficulty in securing an adequate commitment of forces for the Bosnia operation which, like previous EU missions, is also likely to involve forces from non-EU member-states.
The presidency will seek to strengthen the UN dimension of the EU's security policy and will examine a call for the EU to establish a rapid-response capability in support of the UN. Such a capability would mean that the EU could deploy troops to conflict areas within days of a UN Security Council resolution.
Irish officials stress that the EU's security strategy calls for action to deal with the causes of conflict as well as its consequences and the presidency will look at how the EU can use instruments such as trade policy and development aid to prevent conflicts.
"The EU has a range of instruments that other international organisations don't have and these can all be used for conflict prevention," said one senior official.
The latest draft of the EU's constitutional treaty calls for a mutual defence commitment which Ireland and other neutral member-states find unacceptable. If negotiations on the treaty resume during the next six months, a compromise is likely to make the mutual defence clause voluntary.
The Government acknowledges that a treaty containing a mutual defence clause has little chance of passing a referendum in Ireland but it wishes to preserve the inclusive nature of EU security and defence policy by avoiding the necessity of an opt-out clause. A further area of controversy in the draft treaty concerns conditions under which a group of countries could co-operate more closely on defence in the EU's name.
There is a broad acceptance among EU leaders that any military operations under an EU flag would have to be approved by all member-states, even if only a few are participating.
The precise arrangements have yet to be agreed, however, and the issue is likely to be among the last to be determined if the treaty negotiations resume.