Britain remains ready to act to “defend freedom of navigation”, foreign minister David Cameron said on Sunday in the wake of joint US-UK air strikes on Yemen. “We’ve demonstrated that we’re prepared to follow words and warnings with action and that is incredibly important,” Cameron told broadcaster Sky News. He suggested further strikes could occur if the Houthi rebels, who control much of Yemen, continue to target ships in the Red Sea. “We have to act. Not acting is also a policy and it was a policy that wasn’t working,” he said. “It’s not just the goods that are coming to this country… it …