The narrowing of Iran's political spectrum will be demonstrated on Friday in parliamentary elections dominated by hardline candidates.

Driving the news: An estimated one-third of sitting parliamentarians were disqualified from participating, reformists were barred en masse, and boycotts are expected from portions of the increasingly disenfranchised population.

109 American troops suffered traumatic brain injuries as a result of Iran's Jan. 8 missile attack on U.S. bases in Iraq, the Defense Department said in a statement Monday.

Why it matters: The development, first reported by Reuters, is a significant jump from the 50 cases the Pentagon disclosed in late January — and more than triple the number disclosed in the immediate aftermath of the strike.

An increasing number of Iranian students are being turned away from entry points when arriving at U.S. airports amid heated diplomatic tensions between the two nations, the New York Times reports.

What we know: Boston's Logan International Airport rejected an Iranian student, Shahab Dehghani, 24, on Monday, even though he had a valid student visa. The refusal sparked airport protests on the student's behalf. Although a petition for him to stay was eventually granted, Dehghani had already been sent back to Iran.

Iran has built up a vast network of proxies through which it wields influence across the Middle East, and which could take action to stoke tensions between the U.S. and Iran over the killing of Gen. Qasem Soleimani.

Why it matters: The political parties and militias that are influenced by and act on behalf of Iran likely pose a more direct threat to U.S. targets than Iran itself, the Washington Post writes.

Iran's Supreme Leader Ayatollah Khamenei told a crowd of his supporters the U.S. is an "arrogant power" and that God had allowed Iran to "slap the face" of the U.S., The New York Times reports.

Why it matters: Khamenei gave the rare public sermon on Friday to present a unified image of Iran to the rest of the world after recent escalations with the U.S. and an Iranian military accidentally shot down a civilian plane. The killing of all 176 passengers — including 82 Iranians — sparked protests across the country.

Iran's former crown prince entered the Hudson Institute, a conservative Washington think tank, to a standing ovation on Wednesday before calling on the U.S. to support the will of the Iranian people — to bring down their government.

Between the lines: Some might question Reza Pahlavi's status as a spokesperson for the Iranian people. He hasn't stepped foot in Iran since his father, the shah, fled the country in 1979.

Iran's president warned today that European soldiers in the Middle East "could be in danger" after three nations — Britain, France and Germany — challenged Tehran over breaking the limits of its nuclear deal, the AP reports.

Why it matters: President Hassan Rouhani's remarks in a televised Cabinet meeting represent the first direct threat he's made to Europe.

Sen. Tim Kaine (D-Va.) said Tuesday that he's secured the 51 Senate votes needed to pass a revised version of his war powers resolution, which would require President Trump to seek approval from Congress before taking further military action against Iran, per the AP.

Why it matters: The bipartisan resolution, which has the backing of Sens. Mike Lee (R-Utah), Rand Paul (R-Ky.), Susan Collins (R-Maine) and Todd Young (R-Ind.), illustrates the degree to which the Trump administration's actions against Iran have tested the president's Republican allies.

The leaders of the U.K., Germany and France said in a Tuesday letter that they are triggering a "dispute mechanism" in the Iran nuclear agreement in response to Tehran’s attempts to undo parts of the deal, the AP reports.

Why it matters: The action could lead to the restoration of European sanctions on Iran that were rolled back in 2015.

Protesters stared down Iranian riot police in at least two cities as demonstrations over the downing of a Ukrainian passenger plane entered a third day, the New York Times reports.

Driving the news: Amid the protests, Iranian authorities announced the arrests of "some individuals" over the crash — without specifying who or how many — and Iranian President Hassan Rouhani called for the creation of a special court regarding the incident, per the AP.