Task: Determine the prevailing emotional tone of the tweet, categorizing it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that most accurately represent the tweeter's mental state.
Tweet: Our soldiers in war zones are held to a higher level of rules of engagement than our police officers. #sad
This tweet contains emotions: 
disgust, pessimism, sadness