Of all the nights Serj Tankian has stood on stage surveying a crowd of 50,000 faces roaring his own words back at him, there is one that the System of a Down frontman will never forget. On 23 April 2015, the metal band gave a two-and-half hour, 37-song set to a rapturous audience in Republic Square, in the heart of the Armenian capital Yerevan. For a band formed in the diaspora community of Los Angeles’ Little Armenia in 1994, the occasion could not have been more significant: they had been invited to perform in the country for the first time as part of events marking the centenary of the Armenian genocide, in which an estimated 1.5 million Armenians were killed between 1915 and 1922. “The overwhelming feeling was of belonging,” says Tankian, 53, speaking from his airy home studio in Los Angeles. “It felt like we were created 21 years earlier so we could be there that night.”

For Tankian, whose outspoken political activism often animates his songwriting, seeking international recognition of the Armenian genocide has been a lifelong and personal campaign. On stage that night in Yerevan he told the story of his grandfather Stepan Haytayan, who was just five years old when he saw his father murdered in the atrocities; he later went blind from hunger. Between songs, Tankian railed against Barack Obama’s resistance to using the term “genocide” to describe the atrocities after taking office, before turning his ire on Armenia’s authoritarian president, Serzh Sargsyan. “We’ve come a long way, Armenia, but there’s still a lot of fucking work to do,” Tankian told the audience, before calling out the “institutional injustice” of Sargsyan’s administration and demanding the introduction of an “egalitarian civil society”.

Tankian performing in Republic Square in Yerevan in April 2015. Photograph: Karen Minasyan/AFP/Getty Images

“I haven’t told anyone this, but the government [had previously] invited me to speak right after Putin at an event the next day, which was a huge risk on their part,” says Tankian, a glint in his eye. After some sleepless nights, he decided to reserve his oratory for the show. “The stage is my domain. What I needed to say could be said there and be heard, so that was the perfect way of paying homage to the recognition of the genocide while being critical of a corrupt oligarchic regime.”

That regime would be toppled three years later by a remarkable peaceful revolution led by former journalist Nikol Pashinyan. In early 2018, Tankian watched over shaky social media streams as Pashinyan gathered his supporters in the square where his band had performed. “He called on myself and other diasporan Armenians to come to Yerevan and join our people in their struggle for progress, democracy and transparency,” says Tankian. “I went as soon as I could.”

When he arrived, Tankian was taken aback to learn that it was, in part, that night in Republic Square that planted the seed of revolution in Pashinyan’s mind. “He said: ‘You know, I was in the crowd in 2015 at the System show and thought: If you can bring 50,000 people here, we should be able to bring enough people here to change the destiny of this country.’” Tankian’s eyes widen as he mimes a double take. “I was like … what? My only response was: ‘It was a cold day. Weren’t you cold?’”

Pashinyan, who Tankian now counts as a friend, was elected prime minister in May 2018, but has seen his administration thrust into crisis since Armenia’s defeat in the war in Nagorno-Karabakh last year. Nagorno-Karabakh is a disputed territory that lies within the borders of neighbouring Azerbaijan, but is predominantly controlled by the Armenian-backed breakaway Republic of Artsakh. “To go from such a high point in Armenian history as the 2018 peaceful Velvet Revolution to two years later this violent war enacted on the Armenians of Artsakh by the combined forces of Azerbaijan and Turkey is devastating for our people,” says Tankian. “To see Turkey, whose predecessors the Ottoman Turks committed the genocide in 1915, attack Armenians in Artsakh felt like an existential peril.”

Last November, with fighting still continuing in Nagorno-Karabakh, System of a Down released a pair of singles to raise awareness of the conflict: Protect the Land and Genocidal Humanoidz. The band have a long tradition of putting their politics on record. They closed their 1998 self-titled debut album with the track PLUCK (Politically Lying, Unholy, Cowardly Killers), an explicit call for “recognition, restoration [and] reparation” in relation to the 1915 genocide. Writing that song was part of an oath Tankian made to his grandfather to “always work to have his history properly recognised by the country he died in, the United States”. In 2019, Congress finally passed a resolution formally recognising the Armenian genocide. That victory came after decades of campaigning which shaped Tankian’s politics. “I thought: there must be so many other things that are being hidden under the rug by the US government,” he says. “I was an activist before becoming an artist. As my bullhorn became louder, through the success of System of a Down, my messages became more pronounced and wider-spread, and so did the repercussions.”

The band’s second album, Toxicity, went straight to No 1 on the Billboard charts in 2001, selling 220,000 copies in the first week. Lead single Chop Suey! remains so well-regarded in the genre that earlier this year the magazine Metal Hammer named it the greatest song of the 21st century. For Tankian, the album’s continued acclaim is overshadowed by the circumstances of its release – just seven days before 9/11. “When I think of Toxicity the last thing I think about is my band’s success,” he says. “What I think about is the crazy stress involved.”

Tankian, with Nikol Pashinyan, just prior to the latter becoming Armenian prime minister. Photograph: Thanassis Stavrakis/AP

Two days after 9/11, Tankian published an essay on the band’s website titled Understanding Oil, which he calls “a sober analysis of the failure of American foreign policy to rein in extremism”. The band’s label Sony disagreed. They took the post down and accused Tankian of attempting to justify terrorism. “At the time, nobody wanted to hear it. There was a lot of flag-waving and a lot of anger. The band called me in and went: ‘Are you trying to get us killed?’ I said: ‘But it’s the truth!’ They went: ‘We know it’s the truth, but who cares? Why are you trying to get us killed?’ I’ve always been naive to think that if something is true, then it should be said. I’m still that naive.”

It would not be the last time Tankian feared for his life on stage. In Truth to Power, a new documentary about his activism, Tankian states that while touring System of a Down’s 2005 albums Mezmerize and Hypnotize he received word “from a very reliable source that there possibly could be Turkish intelligence sources looking at me to assassinate me because of my activism against Dennis Hastert”. Hastert was the then speaker of the House of Representatives who was accused by an FBI translator of taking bribes from the Turkish government. Tankian darts from side to side in his chair as he demonstrates how he’d act during shows so he’d at least be harder for a sniper to hit. “Here I am on stage playing Chicago going from left to right at 50 miles an hour,” he says jovially. “I’m joking now, but I’ve had incredibly stressful times because of all this.”

The following year, System of a Down went on hiatus; while they returned to touring in 2011, they are yet to release another album. Last year’s pair of singles represented the first new music that Tankian, guitarist Daron Malakian, bassist Shavo Odadjian and drummer John Dolmayan had released as a collective in 15 years. “I think it’s very encouraging that we were able to galvanise to do those two songs for our people and work on something outside of our own egos,” says Tankian, though he demurs on whether they’ll ever make any more. “Time will tell,” he says.

The last attempt was made around five years ago, when Tankian presented a collection of new songs to his bandmates. It didn’t work out. “I had a vision for a way forward for the band, along with the songs,” he says. “I don’t think philosophically we were able to see eye to eye.” A musical vision, or something broader? “Musically, how we contribute, splitting of publishing, all of the above,” he elaborates. “It was an egalitarian attempt – I was being the activist within the band!” He’s now releasing those tracks as a solo EP, Elasticity, which demonstrates that Tankian’s songwriting has lost none of its political bite or musical eclecticism.

While his bandmates resisted that particular campaign, Tankian’s activism remains undaunted. He is driven, he says, by the memory of a crowd in Yerevan. Not the one watching System of a Down in 2015, but the masses who swarmed on to the streets three years later to herald their peaceful revolution. “I’ve seen lots of happy, partying people at festivals before, but that day I saw elation in people’s eyes for the first time in my life,” he says. “That’s something I’ll never forget. I hope Armenia returns to that feeling one day soon.”

• Elasticity is out now on BMG.