The United States, Canada and over 100 other countries are party to the International Convention on Road Traffic.

This Convention is intended to establish uniform reciprocal privileges on matters such as drivers' permits. The agreement also requires the US and its states to allow a foreign driver admitted to the US to drive a private motor vehicle for one year with certain conditions.

The United Arab Emirates (UAE) is not a part of this international reciprocal agreement so it should be up the specific state(s) he plans to drive in if they will accept his UAE driver's license as proper licensing proof to drive on the roadways.

Thus it is up to each individual state and state law to determine if one is allowed to drive in a state with the UAE or international license. Your brother should thus check with the state or states which he plans on driving in while in the US to see if their state laws allow him to drive legally within those areas. The Department of Motor Vehicles of each state should be able to provide him with this information.

He may be able to get specialized auto insurance with his foreign or international license but most mainstream insurance companies require a policyholder to have a driver's license issued by a State within the USA. Some insurance companies will start a policy with a person that does not yet have a US license however the policyholder would need to acquire a State license within a short period of time, normally 30 days.