A panel in Japan’s upper house on Thursday approved legislation for a security policy shift that would allow troops to fight abroad for the first time since World War Two, a ruling party lawmaker said. Opposition lawmakers tried to physically prevent the vote in a chaotic scene carried live on national television. The legislation has sparked huge protests from ordinary voters. The government says the changes to the law, welcomed by ally Washington, are vital to meet new challenges, such as that presented by rising neighbour China, whose recent assertiveness in the South China Sea has upset countries in the region. But opponents say the revisions, which the government aims to get voted into law by the entire upper house this week, violate the pacifist constitution and could embroil Japan in U.S.-led conflicts around the globe.