When I was growing up in the 1990s, the liberal order was unquestioned. The US and Europe were home to stable liberal democracies; they were the role models worth aspiring to for the entire world. Today, I am the health minister in Angela Merkel’s government and I’m deeply concerned about the destabilisation of our societies. The biggest threats to our democracies are not external challengers like China or Russia. They are our internal frictions and divisions.

The situation throughout western societies is very similar: our debates have turned hostile. We have broken into ever-smaller groups; people dehumanise their opponents. We are too concerned about what might separate us instead of what unites us. Loyalties seem to lie with one’s political tribe only. The results are fragmentation, polarisation and mutual hate. Internal cohesion is eroding, the capacity for international cooperation is diminishing.

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Polarisation unfolds along economic and cultural cleavages. In the UK and Germany, many have benefited economically from free trade, while others have not. In both countries some citizens embrace a cosmopolitan society, while others crave regional anchors of identity.

The most salient political issues are wealth redistribution and migration. Our strong welfare states lessen the economic polarisation to some extent. But this also leads to a prominent link between migration and redistribution: uncontrolled immigration into the welfare state can lead to support for redistribution mechanisms going down altogether. Even Milton Friedman once said that open borders are incompatible with a welfare state. So, our migration debates are very contested.

Essentially, both debates are about identity. Two groups have formed. One deems western democracies responsible for global inequalities. They call for permeable borders to let less-developed world regions participate more directly in western wealth. They embrace a diverse and cosmopolitan society. The others feel threatened by social change as it questions their economic status and cultural anchors of identity. They call for stronger border regimes and a clearly defined national identity. The nation is a shelter in a fast-changing world.

In our multi-party system, big tent parties in the political centre can bridge these divisions. My party, the Christian Democratic Union (CDU), traditionally united progressive and conservatives. I am convinced that this is the most noble task for all democratic parties.

I am also fully convinced that diverse societies must not fragment based on age, gender, sexuality, origin, race or religion. Quite the contrary: precisely because our societies grow more diverse, we need a unifying narrative bridging our supposed differences. The answer to diversity is not more tales about differences, but stories about commonalities. Our nations are the home we build together.

We Germans see patriotism more sceptically than those in the UK. The reasons are the atrocities the Nazis brought to Europe in the name of the German nation. Just seeing our national flag at party conventions creates an iffy feeling for many Germans.

Our patriotism will always be much more cautious than its British counterpart. We will always commemorate the shadows of our past and remain firmly committed to European integration. However, a shared sense of belonging of all citizens within liberal democracies requires the emotional framework of the nation state.

To find a common identity bridging cosmopolitan and regional identities, I propose a weltoffener patriotismus. Weltoffen is tricky to translate into English. It roughly means being open-minded towards the world, open to new ideas and cultures. Weltoffener patriotismus does not make divisions based on ethnicity, but defines clear premises based on which everybody can join. If a nation is the home we build together, weltoffener patriotismus offers the foundation that everybody agreeing on a set of rules can stand on.

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How does that translate into policy? As minister of health I am the only minister in my party, the CDU, dealing with welfare state issues. And health and nursing are key symbols of national unity because how we treat the sick and the elderly typifies how we define national solidarity.

Germany is ageing rapidly. We need skilled migration to fill the gaps in our health and nursing sector and seek professionals from abroad. We are signing international agreements with Mexico, the Philippines and Kosovo. These countries boast many well-educated youngsters struggling to find a job who we want to invite to work in Germany. We are setting up a German agency for international healthcare professionals (GAP) to facilitate their transition.

A conservative minister championing migration might sound odd. However, this is my understanding of weltoffener patriotismus. Our message to the people of Mexico, the Philippines and all other nations is: if you share our values and want to work with us, please feel cordially invited. Our message to the citizens of Germany reads: we can be proud of our free society, our values and cultures and national achievements. Not least of those made together with Germans whose parents and grandparents were born elsewhere.

The immigration of international professionals in the health and nursing sector is of benefit to migrants and Germans. It follows transparent procedures and is controlled by state agencies. It is embedded in government efforts to increase the pay and working conditions in the health and nursing sector so Germans do not feel pressures on their wages. At the same time, compulsory language acquisition and integration courses aim for a smooth transition into the German society.

We do not only aspire to fill the gap in our health and nursing sector but to also address the search for a unifying identity. Certainly, controlled skilled migration and thorough integration into society is only one step. But it exemplifies how to deal with emotional issues in a less polarising way: not focusing on diverging interests but on shared values; not separating groups, but bringing them together. Because we can be weltoffen and patriotic at the same time.

• Jens Spahn is the German minister for health