Danimal made some good points on being able to do both. However, you also have to play to your strengths. If your 200 speed isn't that great, but you can keep a strong pace going forever, then you'd want to try to lead the pack and shred up the rest of the field as best you could before the final bit of the race to decrease the probability of you getting outkicked. Conversely, If you have better 200m speed then the rest of the field, but you're a little bit shaky in the endurance area, you'd want to just try to hang onto the front runners until that last bit and then try to tear them apart that last 200m (I had a friend that did this in the 800 all the time. Worked great for him and he managed to get 17th in state his senior year). However, both of those only really work at a Highschool and some collegiate levels.
Optimally, you want to be able to spend most of the race around 2nd place (give or take a position) and be able to outkick everyone the last 200m or so. However, that is really difficult to do as it requires total fitness for the event, both endurance and excellent speed. Thats how you win at the elite level.
But since I'm doubting you're at the elite level, the best way to win is to play to your strengths with your strategy, and hope that your strengths outdo your weaknesses.
Participant