Whether it is generic religious bigotry, alarm at the success of Christian missionaries at making converts, or simple xenophobia, Tehran has been cracking down on its tiny Christian minority of late, so much so that even the EU has noticed.
Yusef Nadarkhani, an evangelical pastor and the father of two, has been sentenced to death for converting from Islam, and the Iranian Supreme Court in its wisdom has upheld the decision. In a deeply barbaric proviso reflective of medieval wars of religion at their worst, the court states that Pastor Nadarkhani’s life will be spared if he recants his conversion and returns to the merciful and humane form of Islam so vigilantly upheld by the pious and enlightened mullahs of Iran. Otherwise, if an investigation confirms that he was at one point a Muslim, he will hang by the neck until dead.
From Réalité-EU, a timeline of repression:
In 2008, the Iranian parliament approved a bill mandating that all male apostates be put to death and all female apostates be imprisoned for life. Anti-Christian activities also targeted traditionally protected Christian communities.
In March 2009, after receiving threats from the government, the Assyrian Pentecostal Church in Tehran closed its doors. 
Today, most of Iran’s Christians meet out of sight of the authorities in “house churches”. 
In the early morning hours of December 26, 2010, the Iranian government arrested 25 Christians in Tehran and other locations. 
In January 2011, Iranian authorities arrested dozens of Christian converts from Islam. Tehran’s governor, Morteza Tamadon, confirmed the arrests and said that missionary evangelicals are a “cultural invasion of the enemy”. He described Christians as “hard-line” missionaries who have “inserted themselves into Islam like a parasite,” according to the official Islamic Republic News Agency. 
This statement echoed a declaration of Iran’s Supreme Leader, Ayatollah Khamenei, who in October 2010 said that house churches are a threat to Iran’s national security. 
Those statements serve as the pretext for the Revolutionary Guard’s targeting of churches, their leaders and worshippers. 
In the past six months, the crackdown has led to the arrest of 285 Christians in 35 cities, according to Elam Ministries, an organization that serves Christians in Iran. 
Many of those Christians have spent weeks and even months in prison, often serving long periods in solitary confinement. They also have endured interrogations and psychological abuse. 
[footnotes found on original site]
Interestingly, like many stories of Christian persecution in the Middle East and elsewhere, the stories of Iranian Christians and Pastor Nadarkhani have received widespread attention in the US religious press — and are covered much more episodically and lightly if at all by mainstream outlets. The contrast not only undermines public credibility in the mainstream press as readers take this as evidence of an anti-Christian or anti-western PC bias in the press; it blinds those who rely on mainstream reports to the actual state of US public opinion.
For many Americans, evidence of how Iran treats its Christian minority is an indicator of the kind of uses to which it would put nuclear weapons. More generally, stories about how Christians are persecuted and restricted in some (not, thankfully, all) Muslim countries reinforce public sympathy for Israel and build support for the idea that Israel must defend itself against an unreasoning and permanent hostility.
Elites who think such ideas are frightening or ridiculous and therefore try not to think about them are almost certain to be caught off guard by US public response to any news that Iran is approaching a nuclear test. They are also surprised when American public opinion so unwaveringly backs Israel — and trip all over themselves as they blame Jewish lobbyists and masterminds for the impact of the persecution of Christians as reported by the Christian press on Christian minds.
And, after blaming Jewish machinations and bribes for the attitudes and policy stands of Christians, they then wonder why so many Christian Americans think that many of Israel’s critics are hate filled anti-Semites rather than impartial lovers of justice and truth.