Last month marked six years since the start of the Syrian war, which has forced millions of people to flee their homes in one of the largest humanitarian crises in modern history. Perhaps the artist who has most visibly used his work to draw attention to the conflict is Ai Weiwei, whose political activism has earned him a reputation as China’s foremost creative dissident. Ai has made works focused on the refugee crisis for years, but lately his projects have taken on a greater sense of urgency. His newest exhibit, Law of the Journey, was recently unveiled at the National Gallery in Prague and features a massive inflatable lifeboat with 258 faceless, rubber figures on board—evoking the treacherous journey some refugees make to Europe. Earlier this week, the Public Art Fund announced Ai would build more than 100 fence-themed installations in New York across multiple boroughs, asking the city’s inhabitants to reflect on the ideas of barriers, nationhood, and security.