When the Berlin Wall was torn down 30 years ago, thousands of Germans Celebrated on its remains, heralding the demise of division and confrontation.

While Germans and the world observe the historical event on Saturday, many focused on the wall’s present day metaphor and expressed their worries that new hard frontiers are making a comeback.

Walls and outposts are erected along the U.S.- Mexico border, barbed wire fences have come back in Eastern Europe to shut out migrants from the Middle East, and a protracted Brexit spells trouble for the open borders of the European Union.

Fresh invisible barriers are also surfacing. Across the world, isolationism, unilateralism and protectionism are on the rise as Washington has decided to quit many key international agreements such as the Paris Climate Agreement and the Intermediate Range Nuclear Forces Treaty, and is waging a tariff war against many of its trading partners.

Some are sounding the alarm of a new Cold War. Three decades after the crumble of the Berlin Wall, the zero sum Cold War mentality remains alive and well. Some countries remain ideologically driven. Prone to contain the development of others with different social systems, they even attempt to stage colour revolutions.

These troubling realities reflect that the world today is still a far cry from the optimist picture imagined 30 years ago.

Earlier this year at the Munich Security Conference, the German organisers depicted the world today as a “great puzzle” that scattered into pieces.

But who will pick up the pieces? German Chancellor Angela Merkel’s answer is “only all of us together,” which has sent out a strong message against isolationism, or in other words, the new walls.

Over the past four decades of reform and opening-up, China has benefited tremendously from playing an active and responsible role in the international community. The dividends of China’s development also greatly benefited the world.

To tear down these “New Walls,” Beijing has been trying to join hands with many other countries around the world to boost common development by building the Belt & Road and pooling efforts to combat such common challenges as climate change and terrorism.

China has also been a steadfast upholder of multilateralism and global free trade, and is seeking to work with other countries to bring down trade barriers, optimise global value and supply chains and jointly foster market demand. The Second China International Import Expo is a concrete example of such efforts.

Openness and inclusiveness are what China has been promoting. It should be the zeitgeist that every Country Embraces.