Brexit is an historic setback for the European Union, but not a death sentence. As sad as the referendum result is, it must be respected. After referenda over the European Union's constitution were held in France and the Netherlands in 2005, it was "business as usual." That mistake must not be repeated.
Europe has to prove that it is capable of learning and changing. Reforms can't be made by heads of government behind closed doors -- they should be transparent.
This isn't the time for Europeans to retreat into themselves; it's time for reform. We need reforms that will increase trade, justice, and democracy in Europe. If Europe makes the necessary changes, it would offer hope and counter a populist domino effect in France, Italy, the Netherlands, and other countries.
The problem at hand is that there is too much backroom politics. The Brexit campaign fervently called for a return to self-determination. For weeks, the leading "freedom fighter," Boris Johnson, repeatedly insisted: "We will take back control."
That the Brits have lost control of their country is not true. But it is true that they have felt left out of important decisions.
This is the core problem of today's European Union: Lack of transparency and a democracy that has not yet fully matured.
It's true that Great Britain is one of the most influential nations in the EU's governing council, but since the sessions take place behind closed doors, Brits have no way of knowing the extent of their government's influence.
A return to nation-states through departure from the EU only offers a false promise of independence.
In order for citizens to feel closer to their governments, the doors of the cabinet have to be flung open. This will require an alliance of European and national parliamentarians.
Citizens also need to be empowered. Citizens feel detached from Europe because direct political participation for individuals is so rare.
The European Citizen's Initiative is a good tool in theory. But the EU's Commission reserves too many loopholes for itself, preventing the successful implementation of the people's decisions.
The Brexit referendum and the vote in Austria show that European societies are deeply fragmented. Many people want to regain control and security. But a return to nation-states through departure from the EU only offers a false promise of independence.
If Europe makes the necessary changes, it would offer hope and counter a populist domino effect in France, Italy, the Netherlands, and other countries.
Like the amputations practiced in medieval medicine, Brexit is not a cure. In the face of global challenges, European nation-states cannot secure self-determination and stability on their own. Cooperation with the European Union would make nation-states less vulnerable.
This is where Europe needs to prove itself. At the same time, we have to correct a skewed impression of Europe: The EU isn't a threat, but a sensible evolution of the nation-state.
Europe must become a source of hope and not an enemy. Lack of transparency breeds lack of trust, as we saw with EU Commission's undemocratic negotiations over the TTIP free trade agreement.
Bolstering investment in sustainable energy would be a good step forward. If Europe is to counterbalance social divisions, it must provide more jobs in the future. In light of low interest rates, high unemployment, and urgent political tasks such as shifting Europe's energy sources, such an investment program would be economically sensible, as well as socially and ecologically necessary.
There must be prompt and fair exit negotiations with the UK. The EU's single market is an economic success story, but so is its trade history with the UK.
The British should neither be made an example of nor let off too easy. Giving the UK open access to the single market without rules would be very foolish. The four fundamental freedoms of Europe are a package deal: The free movement of capital in and out of London cannot take place without the free movement of citizens.
This post first appeared on HuffPost Germany. It has been translated into English and edited for clarity.