There are a lot of things to consider as compared to any other job like the CIA or FBI in the U.S. before you decide to become a Foreign Service Officer, also known as a diplomat. If you are a person who is looking for adventure and loves traveling and learning about other cultures, then you can definitely look forward to it.
It is not only a job but a lifestyle which has many perks as well as some drawbacks. One should check out all the resources available online and offline like former/current diplomats to assist you in determining whether or not to join the service.
The first and foremost point to consider, once you decide to join the service is that you are going to live overseas for the most part of your career. There are around 300 US embassies and consulates around the world. Some of them are large and others are relatively small offices.
The most important part of the job is that you represent the U.S. as a diplomat and on duty 24/7. Your actions and behavior represent your country on duty and you should be very careful when speaking in private or public during your posting.