“He who wishes to fight must first count the cost.” Sun Tzu wasn’t just talking about money, but the words of the Chinese philosopher and military strategist should have been playing on Xi Jinping’s mind this week as he announced that China is set to spend $225bn on defence in 2023 – a hefty 7.2% boost compared to last year. Beijing’s build-up of technological and military might has accelerated since Xi took the helm in 2013, and the fresh injection of cash reinforces his ambitious goal to transform China’s military into “a world-class force” by 2049. The People’s Liberation Army already boasts hypersonic weapons capable of evading most defence systems – a technology the US is still developing. China also has the world’s largest navy and 2m active military personnel compared to 1.4m in the US.