The X-Trail of that era has an unbraked towing limit of 750kg and a braked limit of 2000kg. On that basis, the short answer is yes, you need to have brakes on your caravan. But the detail is a little more involved. While you do need a braked trailer (caravan in your case) for the Nissan to handle 960kg safely, those brakes don't necessarily need to be the electric variety. A simpler mechanical braking system would also be acceptable and should work fine on a relatively light van such as the one you've described. Mechanical brakes are preferred by some users who like the fact that the trailer in question can be used on any car with the required towing limit. In the case of electric brakes, a control unit has to be fitted to the tow-vehicle. That gets a bit complicated and is an extra cost. Larger caravan (over 2000kg GTM) need electric brakes, but mechanical brakes are fine for smaller, lighter vans.