PARIS—French President Emmanuel Macron on Thursday inaugurated a posthumous installation conceived by the late artist Christo that envelops Paris’s Arc de Triomphe monument in 2,500 square meters of silvery blue, recyclable plastic wrapping. “This is the achievement of a 60-year-old dream, a crazy dream come true,” said Macron, who was accompanied by his wife Brigitte and officials ranging from Culture Minister Roselyne Bachelot to Paris Mayor and presidential hopeful Anne Hidalgo. Macron said he was particularly happy the installation took place at the Arc de Triomphe because the monument had “suffered so much at the end of 2018,” alluding to the looting and vandalism at the Arc de Triomphe during an anti-government “yellow vest” protest that degenerated in December 2018. Imagined in 1961 by the late Bulgarian-born artist Christo, “L’Arc de Triomphe, Wrapped” was finally brought to life by Christo’s nephew, Vladimir Yavatchev, at a cost of about 14 million …