southern front:
during last three decades, Iran successfully neutralized threats from North (soviet), West(Saddam and ISIS) and East(Taliban) but threat at south is still remain and need to neutralize rapidly otherwise they would hit Iran assets and interest in west and central Asia.
Iran does not have land border with non of the PGCC countries and all of them are Iran sea neighbors; in addition all of these countries have big American bases inside their territories, so they became Good assets for Americans to launch war against Iran from there but for many reasons that would not happen b/c this bases are known for Iran army and Iran would not hesitate to hit bases with it's ballistic missiles also that would provide good excuse for Iran to hit PGCC's Infrastructure as well.
as we can see in map most of the PGCC Infrastructures and population are near to Iran coasts in other hand Iran big cities and most of Iran's population are far from front line and hard to reach by Americans from southern front.
also I believe countries like Oman, Kuwait, Qatar and UAE would stand against Saudi and Bahrain to help Americans to attack Iran from their territories.
as result PGCC countries just would give their air borders to American for Attack Iran, furthermore they would provide money for Americans to break cost of war with Iran.
Diego Garcia Island:
Diego Garcia Island in Indian ocean is one of big American bases independent from host countries opinion, so American can use this base how they like.
this base in Indian Ocean is far enough from Iran main land to support American war against Iran without considering Iran big retaliation.
also this base is near enough to Iran to support American Naval forces to attack Iran.
we spoke about all of four fronts (west-north-east-south) and we found that war with big probability would come from south and there is really small probability for war in other fronts.
Iran just have sea borders in south, so American would attack Iran with their naval fleet and Iran Islands and coasts would be front lines in War.
now we finish my first part of fantasy assumption about American war with Iran.
the next parts are :
2. first wave of American attack
3. WAR