Writing in a blog posted to coincide with his appearance at the NATO strategic comms conference in Riga, Latvia, yesterday, he said: "Our adversaries are more advanced than we are."
Aiken added: "Hostile states such as Russia reportedly spend between $600m and $1bn annually in sophisticated disinformation campaigns."
This investment is set against a media landscape that "has changed radically in the past two decades".
He said: "Where once editors and journalists moderated public discourse, we have a more ungoverned online information space where sensationalism and anger are some of the key determinants of popularity."
Another issue is that the "public don’t yet see disinformation as a problem", according to Aiken.
He cited research showing that while the under-30s have "the highest confidence levels in identifying untrue content on social media" they are also "the most likely to believe conspiracy theories and least likely to trust traditional news sources".
The government comms chief commented: "Disinformation is an area in which our adversaries will always have certain advantages. Hostile states and terrorist groups lack our commitment to facts, consistency and credibility."
Referring to the nerve agent attack on ex-spy Sergei Skripal and his daughter Yulia in March this year, he said: "In the aftermath of the Salisbury incident HMG quickly faced more than 30 false narratives spun by the Kremlin."
Yet Aiken claimed that "while fake news can temporarily beat fact, it cannot overcome a compelling story based on the laws, values and standards which underpin the rules-based international system".
In his view "we are demonstrating our ability to counter disinformation or building capability where gaps have been identified".
Aiken said: "In the face of Russia’s cloud of lies after Salisbury, we stuck to the facts, focusing on building respect and winning the trust of our audiences rather than rebutting every false Russian narrative."
In the aftermath of the nerve agent attack in Salisbury, the Prime Minister, Theresa May, accused Russia of a wider agenda, where it is "seeking to weaponise information, deploying its state-run media organisations to plant fake stories and Photoshopped images in an attempt to sow discord in the west and undermine our institutions".
The Government’s rapid response unit, set up to counter fake news, and the expansion of the national security communications team are among a series of measures that are being taken because "disinformation is a continuing threat to our values and our democracy", according to Aiken.
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