America's influence on the world scene will decrease between now and 2020, with other powers such as China, India and Brazil stepping in to secure their global share, thus transforming the world from a unipolar to a multipolar system, according to the authors.
So the question is not whether the international system will be multipolar but how this system will evolve, argues the December paper.
In the "undesirable" model, the various poles would coalesece into two hostile alliances, with the West lining up against "an axis of autocracies" (such as Russia or China) and the West versus Islam respectively - a scenario that could emerge following a Western attack on Iran, the authors state.
By contrast, the "desirable" model of multipolarity would be multilateral in nature, with all the poles committed to the rule of law and playing an active role in international institutions and treaties, the CER paper says.
Much will depend on Europe if the latter scenario is to become a reality, since the US, China and Russia are all capable of both multilateral and unilateral behaviour, according to the analysis.
The authors make seven concrete recommendations for the EU to follow in order to improve Europe's weight in the world:
1. A successful European economy. The perception that Europe is over-regulated and undynamic undermines the EU's 'soft power'. An economic reform agenda should prioritise a stronger competition policy, new schemes to attract skilled migrants and the further liberalisation of energy and services markets.
2. The EU should lead the world on climate change. If Europeans can make their own carbon-trading scheme a success, persuade the Americans to sign up to a global system and offer their environmental technologies to developing countries, they may convince most of the world to join them in a new system after Kyoto expires in 2012.
3. Continue EU enlargement to include predominantly Muslim countries such as Turkey. By doing so, the Union would gain more influence and respect in many parts of the world.
4. Strengthen the capabilities for delivering common foreign and security policies, namely by recruiting sufficient personnel to the external action service (EAS), which EU leaders agreed to set up in the Lisbon Treaty, and showing a clear commitment to deploying its forces around the globe.
5. Improve co-operation on justice and home affairs (JHA). As the Union will become much more involved in issues such as counter-terrorism, illegal immigration and organised crime, the EU should think about creating an Internal Action Service (IAS) by 2020, modelled on the EAS. By creating IAS, the existing EU agencies in the field of JHA could be forged into a single organisation and thereby improve their efficiency.
6. The EU has to maintain its strong support for international law and make an effort to renew the institutions of global governance. A priority would be the creation of a uranium bank, which – under the auspices of the IAEA – would supply fuel to all countries with a nuclear energy programme and by doing so, remove their need to operate their own enrichment cycles.
7. The Union must engage constructively with other global powers, including undemocratic ones, giving clear preference to the relationship with the US.
The authors conclude by saying that if Europe fails to persuade others of the benefits of multilateralism, its citizens will face a "very bleak 21st century".