Dozens of soldiers clutching AK-47s and grenade launchers watch over roaring bulldozers on the white sand beach that meets a tropical turquoise sea. They’re guarding Africa’s biggest investment: a $23 billion project to export Mozambique’s natural gas from an area increasingly besieged by an Islamist insurgency. Companies led by Total SA will pump the gas from wells about 40 kilometers (25 miles) offshore, cool it to temperatures below minus 260 degrees Fahrenheit so that it turns to liquid, then ship it to electricity plants from France to China. The consortium is about to finalize almost $16-billion in project financing — another record for the continent.