In 2015, 900,000 refugees and migrants crossed through Southeast Europe in the largest displacement of people since World War II.  Many crossed from Greece to the former Yugoslav Republic of Macedonia and Serbia on their way to northern Europe.

Most towns on that route were taken by surprise. Many didn’t have the doctors, food stocks, waste capacity, or sufficient housing to handle hundreds of thousands of additional people. Their whole approach to planning was suddenly upended. And many refugees ended up staying for months.

Displacement in this region is not a new phenomenon. But over the last two years, we’ve learned many things about how to deal not just with the humanitarian side of displacement, but with the long-term impact. These are the seven things we know so far:

1. A history of displacement can create empathy

The Western Balkans has experienced its share of displacement, in the midst of the conflicts of the 1990s. Many people remember being on the receiving end of assistance and were welcoming to newcomers, giving away sandwiches, clothes, and medical supplies. Some even provided temporary accommodation. But this puts pressure on top of existing economic and social problems and after a while, it’s essential that governments step in to relieve people.

2. Sudden population movements revealed the region’s fragility

The crisis put untenable pressure on communities already facing economic hardship and tensions with neighbors. Governments and towns were unprepared for crisis, let alone a huge population influx. In Serbia, many services were already suffering from austerity. Collaboration between police and NGOs was non-existent. This stresses the need for better local planning and funding of development efforts, hand in hand with civil society and businesses.

3. The local impact of displacement can be intense

Local authorities and communities are on the frontline and need to be represented in national responses. They understand better than anyone the problems caused by the refugee crisis. To respond effectively, they have to be allowed adaptability and flexibility to deliver necessary services. At the same time, municipalities should develop ways to work with each other. If one creates a good cash assistance programme, then others should know how it works.

4. Environmental consequences weren’t considered enough

The environment shouldn’t be a necessary collateral damage from the crisis. Migrants and refugees received pre-packaged blankets and diapers, but because they couldn’t carry them across borders, many people threw them away. These overloaded landfills and even caught fire, generating resentment from locals. Waste programmes need to be designed to accommodate such risks.

5. Many mayors face challenges in planning for future inflows

“If I send signals that I’m expecting this to happen again, residents will leave,” said one mayor. It’s essential leaders communicate effectively with their citizens. If we do not inject resources into helping both host communities and displaced people, the message should go, then the crisis may hit you hard next time.

6. Mosques, churches, and local civil society organisations are key actors

These groups acted as critical first responders. They hosted refugees and gave them basic necessities before governments and international organizations did. Local community groups helped ease friction from underlying fears. If anything, these groups are now shrinking. It’s vital we invest in them.

7. Better technologies and skills will make a big difference

Municipalities used different registration systems for people passing through. Local authorities should share standardized technology and train police the same way to handle migrants, and to protect their safety and dignity.

The refugee crisis was a wake-up call for local municipalities in the Western Balkans to better prepare for sudden crises. It’s not building walls that they need, but more efficient ways of coping.