The treaties aim to help member states to bring prosperity and liberty to their respective people, while respecting the attachment of these people to their nation state.
Some states are less successful at economic management, he said.
The EU has faced crises of declining competitiveness and demographic decline, as well as Brexit and the pandemic, he said.
Germany will need 400,000 immigrants a year, because of declining population, he added.
These crises accelerate the divisions between member states and call into question the EU’s foundations, its values, and the principle of the whole order.
While EU values are the heart of the identity of Europe, Europeans are different because of differing conceptions of life, he said.
The current political reality is that most member states refuse to fulfil their Treaty commitments, because of decision-making rules that were adopted for a club of six.
Any member state has a veto, which means the legal power to prevent the EU from meeting its commitments.
Discussions between five or 16 members generally led to a consensus, he said, but the union's capacity to absorb new members will need operationally effective reforms.
There is no leverage for the member states to agree on treaty changes, even though the EU is involved in several serious crises, he said.
“My personal opinion is that it must involve 20 changes,” he said.
“Of course, I know that the member states are not ready to open that discussion,” he added.
“It will not happen in the short term.”
“However, I must stress that the EU is unable to fulfil its essential task with its current decision-making,” he said.
This is before any enlargement that could include the six Balkan states.
The EU is also trying to become a more credible actor on the international scene on key issues which require unanimity, he said.
“The number of cases where unanimity common agreement or consensus are required is much, much bigger than people think,” he pointed out, adding that this included any change of the treaties, and any issue concerning foreign-and-defence policy, health, protection of the environment, climate change, social policy, family law, and the internal market.
An individual veto should be reserved for a shortlist of vital decisions, because an individual veto “is neither democratic not efficient” if it prevents representatives of a big majority, or one member out of 27, from taking any major decision.
There are eight member states that each have fewer than 1% of the citizens of the EU, and 13 with fewer than 2%, he pointed out.
Even aspects of policies affecting the single market must be decided unanimously.
The life of EU citizens must be represented in a more democratic way in this decision-making procedure, he said.
There are many cases of veto which are not vital for any member state, he said.
While differentiation is not a panacea, given the differences of wishes and needs between the 27 member states, various ways to differentiate between them should be encouraged if the level playing-field is respected, he said.
DCU Brexit Institute’s Federico Fabbrini responded that he has been pushing for reforming the EU in his writing.
“It was really good to hear to hear you say the same when, in fact, many member states are reluctant, and the Council always indicated that the institutions are stopping any reform process.
“I think that was refreshing,” he said.