What are the 'Gulf nations' as war in the Middle East intensifies?

War in the Middle East intensified as Iran, following US and Israel's attack, launched strikes in the Gulf nations. Gulf nations refer to Gulf Cooperation Council's members - Saudi Arabia, UAE, Qatar, Kuwait, Bahrain and Oman. These countries are located on the Arabian Peninsula and border Persian Gulf. While Iran also borders Persian Gulf, it's not a part of GCC.