Book excerpt: At a time of alarming global instability, amid shocking terrorist attacks in Europe and mounting tensions between the USA and North Korea, a clear and focused foreign and defence policy is now more critical than ever. Now that departure is under way, what happens next? Against this unpredictable geopolitical backdrop, Britain's position in the world needs to be recalibrated to take account of a range of new realities. Now is the time to move forward, to define a positive, outward-looking role in this post-Brexit world. British Foreign Policy after Brexit examines what lies ahead, encompassing a diplomatic, security, development and trade agenda based on hard-headed realism. Former Foreign Secretary David Owen and former diplomat David Ludlow, who backed opposite sides in the referendum, together argue that Britain's global role and influence can be enhanced, rather than diminished, post-Brexit.