It is an ICAO requirement for international operations and all the member states require their crew members to have it...., the US is a member state so you do need it....! It's quite easy to get.

Pardon me for asking but...., Is this validation of your license for a job abroad?
If it isn't then disregard my next comment but if it is, let me give you a bit of unsolicited advise.

The least you ask Why? The more enjoyable your experience will be...., if you start questioning and comparing everything, you will be ****ed off and miserable rather quickly.