Editor's Note: September 21 marks the United Nations International Day of Peace. In this episode of "Come Together," CGTN looks at the behind-the-scene story of a Chinese peacekeeper and China's efforts in UN peacekeeping missions.

Two years ago, a photo capturing the touching moment when a Chinese peacekeeper and his wife reunited went viral on social media. Titled "Kiss for Peace," the photograph aroused people's curiosity about the story behind.

"That morning, he just said 'I'm leaving,' and then went his way. I didn't see him off," recalled Xu Mengsha, wife of peacekeeper Wang Xianglong, whose happy reunion was forever frozen in time in the photo.

"She was lying in bed, and didn't say a word to me when I told her I was leaving. When I turned towards her, she was crying with her face buried in the duvet," Wang said.

Valentine's Day in 2016 was of special importance to the couple as they tied the knot. But the very next morning, Wang had to say goodbye as he embarked on a yearlong UN peacekeeping mission in Liberia.

Wang was assigned challenging tasks including the removal of old camps. What he worried about were the sudden outbreak of demonstrations and armed attacks during patrols.

"You'll never know when you'd be shot by someone behind you," Wang told CGTN from his office in Zhoushan, east China's Zhejiang Province.

According to the United Nations (UN), peacekeeping missions have proven to be one of the most effective tools available to help host countries navigate the difficult path from conflict to peace. The first UN peacekeeping mission started in 1948. Today, the UN peacekeeping force consists of around 11,000 police officers from 88 countries, fostering international peace and security by supporting countries in conflict, post-conflict and crisis situations.

"They play a role between the military and individual police officers, which can be beyond the capacity and capability of an individual officer. They provide community policing as well as building the capacity of the host nations," said Ata Yenigun, a former UN police adviser.

"A country that has benefited from UN peacekeeping mission stands a 50-percent larger chance of not relapsing into conflicts. So, it's not a reduction by 100 percent, but at least that's another 50 percent better," noted Herve Ladsous, former UN under-secretary-general for peacekeeping operations.

From 1990 to 2018, some 39,000 Chinese personnel participated in UN peacekeeping missions. By September 2017, China had registered an 8,000-strong standby peacekeeping force at the UN. Among the permanent members of the UN Security Council, China is the largest contributor of peacekeepers and one of the major contributors of funds to UN peacekeeping missions.

"One day, a kid ran to us and saluted us. I felt so happy that the locals appreciated our efforts," Wang said.

On March 20, 2017, China's fourth UN peacekeeping police team in Liberia returned home.

"I found him dark and thin when he came out of the coach. I had thought about so many things to talk about but when I finally saw him, I was at a loss for words," Xu said.

"We'd been apart for so long that we didn't know what to say to each other. So I just went over (and kissed her)," Wang smiled.

Now, Wang works at the Zhoushan Public Security Bureau in Zhejiang Province. In April this year, the couple welcomed their first child. Besides watching their baby girl growing up healthy and strong, the couple, together with billions around the globe, cherishes a shared wish for world peace.