When people in the West use "Asians" they are using it in terms of ethnicity not geography.
"Asians" as a term in the US is used for CJK and SEA mainly. The truth is those cultures and peoples are broadly related you know? People from South Asia and the Middle East are not. So "Asians" becomes a very inaccurate term when you tried to make it a cultural and ethnic concept when it is nothing more than geographical thing.
Okay, so you live on the other end of this landmass? But so what? What are the cultural and people connections?
Chinese, Japanese, Koreans, Vietnamese, Thais, Filipinos and Indonesians are connected culturally, economically and a broader sense even racially. A Korean, Hmong or Vietnamese can be attacked -- and have been attacked -- for being mistaken for Chinese. An Indian or Armenian would not be.