Nor can expressions of sympathy be offered in expectation of a change in behavior - the idea that this horrific event may make Iranian leaders somehow more amenable to altering their strategy of supporting the Syrian regime and instead focus on defeating Islamic State, which has claimed responsibility for the attacks.
A 24-second video released by the Islamic State group's Aamaq news agency purports to show the siege of Iran's parliament. He did not elaborate.
The bloodshed shocked the country and came as emboldened Sunni Arab states - backed by U.S. President Donald Trump - are hardening their stance against Shiite-ruled Iran.
Putin said the attacks underscore the need for deeper international cooperation to fight terrorism and confirmed Moscow's willingness to aid Iran.
Iran's emergency services said a total of 13 people were killed in the two attacks and 46 wounded.
Tehran claims Saudi Arabia is funding most of these groups, a charge Riyadh denies.
ISIS broadcast video of one casualty on the floor as gunmen fired and shouted in Arabic, "Do you think we will leave?"
The Intelligence Ministry said security forces had arrested another "terrorist team" planning a third attack, without giving further details.
"This is a minor issue but reveals that the terrorists pursue troublemaking", the speaker of Iran's parliament, Ali Larijani, said.
Ayatollah Ali Khamenei, the country's supreme leader, used the attacks to defend Tehran's involvement in wars abroad. It was not immediately clear if the attacks were related.
Top News Gunmen Storm Iran's Parliament AP
"The Iranian nation will go forward", he added.
Iranian Foreign Minister Mohammad Javad Zarif, who was on an official visit to Turkey, strongly condemned the deadly attacks, lamenting that the entire region has been plagued with terrorism and insecurity.
The parliament assault began when four armed assailants, dressed as women, burst into the building complex and attacked the parliament buildings in the morning, reports Tasnim news.
An ABC News reporter in Tehran said he heard gunfire Wednesday afternoon, and shops in the area remained shuttered.
Police helicopters circled over the parliament building and all mobile phone lines from inside were disconnected. He says the Iranian people are "going through such challenging times".
It was an hours-long siege at the legislature that ended with four attackers dead.
Germany is one of the six world powers that were part of the nuclear deal with Iran.
Jaish al-Adl (or the Army of Justice) is a Sunni militant group that has carried out several attacks on Iranian security forces mainly in Sistan-Baluchestan.
The bill is a "carefully crafted response to Iran's ongoing aggression in the Middle East", Sen.
But the shocking nature of the attacks - the first of their kind in the Islamic Republic for years - raises the question of whether and how they will affect Iran's threat perception and anti-terror calculations.