A20 Canada's foreign minister says Washington and Ottawa may be drawn closer to common policies.
It is already very hard for the Union's current 15 members to agree on common policies.
Foreign Minister John Manley said it was still too soon after the disaster to talk in detail about common policies.
How will the EU manage "enhanced co-operation", in which groups of countries forge common policies, while others opt out?
This necessary joint working out of common policies or responses to proposals by cabinet ministers may be fairly informal.
They have also provisionally formed a UK commissioners' group, with the aim of establishing common policies on issues such as asylum and the commercial pressures facing children.
There is less change in the desire for the EU to decide common policies for immigration, but few people wanted that anyway.
It has two main roles: to devise common policies and to run the day-to-day business of the European Union.
The key area of policing and justice is included here, although Britain has secured the right to "opt in" or exclude itself from common policies in these areas.
"In this way, musicians create a dialogue and arrive at common policies," says analyst Frédéric Ramel, a professor at the Institut d'Études Politiques in Paris.
A similar mechanism will apply to "flexibility", the notion that some countries should be able to adopt common policies even if others do not.
