<p>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?<br>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 mov...