Grey‑zone warfare - A Snapshot

Andrew Shearer (Director‑General, Office of National Intelligence) recently warned that democracies are under increasing pressure from authoritarian states via “grey‑zone” methods.

Shearer said these adversaries are exploiting democracies’ openness and preference for restraint and de‑escalation and observed that informal/grey‑zone warfare is “as old as warfare itself,” but the current form is being transformed by technology.

He has also emphasised that we no longer have a long warning period (e.g. a 10‑year strategic buffer) to prepare for major conflict.

But what exactly is grey zone warfare?

Specifically, grey-zone warfare (also called hybrid warfare or sub-threshold conflict) refers to a form of conflict where hostile actions are deliberately kept below the threshold of open, declared war.

The aim is to weaken internal cohesion and sow distrust among allies.

The Australian Defence Strategic Update (2020) defines grey-zone activity broadly:

“Activities designed to coerce countries in ways that seek to avoid military conflict … paramilitary forces, militarisation of disputed features, exploiting influence, interference operations and the coercive use of trade and economic levers.”

This type of warfare blends traditional and non-traditional tactics - such as cyberattacks, disinformation, economic coercion, and proxy operations - to weaken or destabilise a target without triggering a full-scale military response.

Grey-zone warfare is conflict by stealth - It's not about tanks and missiles—but data, influence, and deniable disruption.

Grey-zone warfare sits between Peace (diplomacy, competition, influence) and War (armed conflict, kinetic operations). Operations exploit the ambiguity in international norms, laws, and response thresholds. The goal is to stay "below the radar" of conventional military retaliation.

Why is grey-zone warfare a popular tactic:

• Ambiguity: Difficult to trace back to the source. Deniability is key.

  
  

• Asymmetric advantage: Allows weaker states or actors to challenge stronger powers.

  
  

• Exploits democratic weaknesses: Open societies, free media, and rule of law can be manipulated.

  
  

• Avoids direct escalation: Keeps actions under the threshold of conventional warfare.

Examples of grey zone tactics and techniques include:

• cyber-based attacks,

  
  

• political interference,

  
  

• disinformation,

  
  

• economic coercion, and

  
  

• use of proxy/paramilitary forces.

Grey-zone warfare is the battlefield of the 21st century - less about bullets and bombs, and more about data, influence, and ambiguity.