LONDON—Britain needs to boost its capacity to conduct cyber attacks on foreign enemies, Prime Minister Boris Johnson said before the publication of a national security review next week. “Cyber power is revolutionising the way we live our lives and fight our wars, just as air power did 100 years ago,” Johnson said in a statement released by his office on Saturday. Johnson is due to present a long-term review of national security strategy to parliament on Tuesday which media reports suggest could lead to a reduction in armed forces personnel. “The review will set out the importance of cyber technology to our way of life—whether it’s defeating our enemies on the battlefield, making the internet a safer place or developing cutting-edge tech to improve people’s lives,” Johnson’s office said. In 2019, Britain spent $59 billion, or 2.1 percent of national income, on defence, more than any other large European country …