As an Arab and a Muslim, from the middle east , in simple terms the sunni-shia conflict only exist in the US media and their Allies in English speaking media , I have never heard the term in Arabic media,
so simply, there is no sunni - shia hostility , only propaganda
if you want to know more here is why
the term became popular after the US invasion of Iraq, before that we never asked or cared to know what sect of Islam our neighbors were mixed marriages were common and still in SA and Bahrain people are mixed (As opposite to Iraq were they became segregated )
the US used the "divide and rule" trick to split the Iraqi resistance after the invasion, calming Iraqi shia's are a thread and being sponsored by Iran . the rest
The U.S. Role in Iraqs Sectarian Violence - FPIF
the only countries that might hint to such an issue, Saudi, Bahrain (were the royal density trying to show the popular movement asking for democracy as a shia based revolt, even though the leaders are sunnis )
it is better than saying The US/Israel and their is followers -allies in political terms -Vs the US/Israel opposed countries
on Iranian , Turkish , Syrian , Tunisian , Sudan TV channels for example those countries that do not align with the US policy are called ( Resistance Front , Axis of Resistance , Rejectionist Front )