Sure, but who is a disbeliever ? Anyone who disbelieve in God or associate partners with Allah, even the Pagans of Mecca has the concept of a God, rest are daughters of God. And yet Quran called them disbelievers, my understanding of 12ver Shia's is that they are not believers, but close to to Pagan of Mecca where they elevated the 12 Imams as demi Gods who can Answer prayers, who will determine ones fate on the scale in Judgement day and all, As I said I don't come to my conclusion on empty farts, I read/watch videos from those who have understanding of language and Islamic theology and than make my decision. Shia's can call themselves Muslims I have no issue with them, even Qadiyani call themselves Muslims, Nation of Islam call themselves Muslims, there are Gay clerics in West call themselves Muslims , even ISIS/AQ scums call themselves Muslims, even the Hypocrites of Median/Mecca called themselves Muslims, but does that make them " One " ? Nope.
It's not a matter of your understanding of Islam, or anyone else's for that matter. These verses explicitly refer to those who openly or secretly express their disbelief. I encourage you to read these verses carefully and seek forgiveness and guidance from Allah.