(CNN) Almost a year before the Iowa caucuses, a top US cybersecurity official said fears about foreign meddling in the 2020 election were the one thing that kept him up at night.

But if this week's debacle in the first vote of the Democratic presidential primaries is anything to go by, another formidable threat to American democracy lies much closer to home.

As the hours ticked by Monday night with no sign of results out of Iowa, a lack of information from election officials left a void filled by a torrent of American-made misinformation, conspiracy theories about what went wrong, and claims of vote-fixing.

There is no sign that external interference played any role in the meltdown of the Iowa Democratic Party's reporting system (some of the blame lies with the apparent failure of an app ). In fact, the work that was done to cast doubt over the democratic process -- efforts typically pinned on foreign adversaries and bad actors -- was being done by Americans themselves.

Russia, backed by an army of trolls and bolstered by hacks, in 2016 showed the world that hybrid information warfare could influence an election. One element of Moscow's efforts focused on sowing discord through a coordinated disinformation campaign, according to special counsel Robert Mueller's report . Another involved a "hack and leak" -- including the computer hacking of the Clinton campaign and the leaking of embarrassing emails. The aim of both strategies was not only to discourage voting for then-candidate Hilary Clinton, but to make Americans feel like their vote didn't matter and dissuade them from voting altogether.

The US intelligence community anticipates foreign actors will try to use the same tactics again in 2020, and there are already signs of interference from Russia (Moscow denies all claims of meddling). Late last year, Congress approved $425 million in election security funding, as part of an effort to safeguard against interference. But, with nine months still to go, Iowa is worrisome evidence that the challenge is also internal: misinformation is just as likely to come from inside the US as from outside, experts say.

"If a country can't recognize that domestic disinformation is just as much a threat as the foreign variety then they will be unable to counter either," Nina Jankowicz, a disinformation fellow at the Wilson Center and author of the upcoming book How to Lose the Information War, told CNN.

Sowing doubt in democracy

If the Iowa chaos has taught us anything, it's that we're uniquely vulnerable to narratives of "hacking" and "rigging" thanks to 2016, Jankowicz said.

There are plenty of malign actors, Russia included, ready to capitalize on that vulnerability -- through weaponizing information or amplifying mistruths -- to sow doubt in democracy.

"The media and the political actors in the US have a huge role to play in terms of combatting this type of stuff [disinformation], not being sensationalist and being very clear in the language they use," Jankowicz told CNN, adding that she would like to see more political campaigns pledge not to share or promote disinformation, like Massachusetts Sen. Elizabeth Warren and former Vice President Joe Biden have.

Buttigieg supporters cheer at watch party.

"Anybody who is propping up conspiracy theories -- promoting mistruths or distruths -- is doing a disservice to the democratic system writ large," Jankowicz added.

And it's not a partisan problem. Though the integrity of the actual vote -- which is backed up with paper ballots -- is not in question, actors on the left and right have used the cloud of doubt hanging over Iowa to promote their own political agendas.

Biden's team questioned the integrity of the process , while former South Bend, Indiana, Mayor Pete Buttigieg delivered a "victory speech" before a single precinct had reported, adding to the chaos and giving legs to an unfounded conspiracy that the app was rigged in his favor. Buttigieg later cited his campaign's internal data as the basis for declaring early.

Furious supporters of Vermont Sen. Bernie Sanders speculated about a stolen victory on social media. Meanwhile, those on the right, including the family of the President, fanned the flames with allegations that the caucuses had been "rigged."

Sanders supporters await caucus results.

Looked at all together, experts said the Iowa mess illustrates just how easy it is for any actor -- foreign or domestic -- to amplify disinformation aimed ultimately at suppressing the vote.

In Iowa's wake, Facebook's former chief security officer has warned the campaigns and their surrogates against priming Democrats to believe disinformation

"There is something much more important than spinning a disappointing result at stake here. The campaigns have a critical role to play in keeping their supporters from seeding or amplifying messages that will be used to divide the party and nation come November," Alex Stamos, who has previously suggested the US elections are at risk of becoming the "World Cup of information warfare," said on Twitter

Disinformation thrives in a vacuum

The campaigns aren't the only actors culpable in spreading misinformation.

Graham Brookie, director of the Atlantic Council's Digital Forensic Research Lab (DFR), who was monitoring Iowa for foreign influence, argues that the media also has a big role to play.

The information vacuum and overarching confusion, which could be seen in live television coverage, further fueled disinformation and conspiracies on social media, he said.

"In the case of Iowa, in the absence of information, with delayed results, broadcast media in particular struggled to create enough analysis to fill the time, so turned to speculation ... those 'could-bes' and 'what-ifs' open space for disinformation to seep in. Extrapolate that to the online environment and it gets a lot worse," Brookie told CNN, adding that there needs to be a high threshold for verification when reporting on disinformation, and a very clear delineation between what is news and what is commentary.

Voters watch CNN coverage on election night.

The DFR did not see any signs of Russian efforts to sow further disinformation in the Iowa caucuses, but did see foreign actors glom on to existing polarizing narratives that aligned with their goal to sow more chaos.

That's a tactic that was observed last year, when Facebook suspended Russian Instagram accounts targeting US voters, in the first indication of Kremlin-linked meddling in 2020. Facebook, which owns Instagram, said the campaign mostly recycled existing memes and posts from real American news organizations and political groups.

"In the context of the US elections, the scale and scope of domestic disinformation is much larger than any foreign adversary could possibly do to us," Brookie said.

"It's going to get weirder before it gets less weird."