When we are talking about being obligated, we are normally talking about a duty we should fulfil. Some alternate options to express this concept would be to say "was bound," "was compelled," or "was required." Other frequently used synonyms in such situations could be "had to," "was to," or "was expected to." Depending on the context, there are a plethora of possible synonyms that we could consider, such as "was forced," "was commandment," "was imposed," or "was prescribed." By using these synonyms for the phrase "was obligated," we can communicate more effectively precisely what we need or required to do, making it clearer and more concise.