This is significant because the current government of Iraq is a majority Shia government as is the Government of Iran. Observers have long speculated that Iran has significant influence with them.
In addition, we are now and have been for years supporting the Iraqi government against ISIS with massive economic, military and political assistance and this is one more example of Iran’s increasing its footprint and influence in the region to our disadvantage (as Iran is also doing in Afghanistan with their aid to the Taliban).
It is difficult to see any positive impact in the medium and long term for U.S. interests in the region. The Kurds are one of the few reliable U.S. allies (perhaps the most reliable and capable) and we and everyone else have voiced our opposition to their gaining statehood. Seem only a matter of time before the Iraqi, Iranian and Turkish governments move against the Kurds and then I wonder what our response will be.
Iran Iraq Government Forces To Hold Joint Border Drills