As far as religious footings are concerned there cannot be any similarity between a Shia and a Sunni. The religious understanding cannot be a platform common to both.
“Argue them with that which is good”; is the beacon that the Shia follow in their behavior with Sunnis. Taqia that is to show a face favorable or to behave in correspondence with theirs or to act in a way not to wound the feelings, these dimensions and it’s like is in itself a religious and Quranic one, stands a ground for confronting a Sunni. It is a religious duty to behave well.
The Shia should take care to behave pleasantly towards a Sunni and have such a mutual understanding that could teach him the real fundamentals of Islam and could attract him to the real entity of Islam. He may find guidance as he transacts with a Shia. The minimum that could be expected from a Sunni is that he distances himself from tyrant rulers and their junta.
If one takes a look he can clearly see inside. Speaking without seeing is always contrary to the facts. To revolt is not prudent; to do what is in the interest of Islam; to hold the interest of Islam high, is and has had been the motive of a Shia Imamiah. To revolt is not the absolute necessity; such is the Shia conception. We have examples and we follow them. Ali Bin Abi Talib preferred to remain silent rather than to fight without support. Had he fought the very name of Islam would have vanished.
Of course, he argued and debated; but his endeavors availed nothing. No one heeded what was right. They had surrendered to the authority of Abu Bakr and then Omar and then Othman. Likewise, Imam Hasan made peace with Mawiyah. What they did was not to their own benefit but to the advantage of Islam. However hard they paced and however difficult the toleration, they endured with fortitude. The school of Ahlul Bait was protected with many great sacrifices.
The episode of Karbala is something exceptional. Its type is of its own neither preceded nor can it ever be repeated. It is such a paragon that a Muslim or non-Muslim, anyone, however disappointed, distressed, depressed, disgruntled and deprived would become hopeful and would find a way out. Although that uprising was crushed and seemingly repeated but at length it turned victorious and eradicated the very dynasty of Bani Ummayah and preserved Islam in its originality.
After this upraising of Imam Husayn (as) no other episode took place that should have had been the cause for Shia distress or disappointment. Shia governed the dominion of faith, knowledge, and belief in Ahlul Bait. To confront tyranny in any age is the only power of Shi’ism among Muslims, even alone Shia is the dread of a tyrant no matter whether a ruler or a caliph or a king.