Prime Minister Boris Johnson’s collective-defence deal with Swedish and Finnish leaders represents a shift in the European order—and Britain’s post-Brexit place in it. Our correspondent visits Great Zimbabwe, a long-overlooked archaeological site of stunning proportions whose secrets are only now being revealed. And a look at the weird sensory thrill of ASMR through a new exhibition. For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer