British intelligence fooled Ottomans with a staged dropped haversack

After two failed British assaults on Gaza in 1917, Ottoman and German commanders under Friedrich Kress von Kressenstein were alert to British intentions and skeptical of any information that came to them too easily — exactly the condition that makes direct disinformation (a leaked document, a forged order) unpersuasive, because a wary adversary assumes anything offered outright might be a plant. British intelligence needed the Ottomans to believe the next attack would fall on Gaza again, while the real assault was being prepared against the weaker position at Beersheba.

Rather than transmit false plans through a channel the enemy might suspect, a British officer rode into contested ground near Ottoman lines and, in the course of drawing enemy fire and retreating, appeared to accidentally drop a haversack containing apparently genuine but falsified operational documents pointing to a renewed attack on Gaza. Ottoman forces had to find, retrieve, and independently authenticate the documents themselves — information obtained through the enemy's own effort reads as far more credible than anything handed over directly.

Staged a dropped haversack for the enemy to find, so their own effort in retrieving and verifying the fake plans made the deception feel self-derived and credible.

The enemy found the documents themselves, so they seemed authentic.

Effort invested in retrieval made the information feel self-derived.

Direct delivery would have been dismissed as a plant, but discovery bypassed that.

Even doubt was overcome because the enemy had to verify the find.

To convince a skeptic, let them discover the information themselves; effort spent obtaining it boosts credibility.

British and Anzac forces took Beersheba on 31 October 1917 against a defense weighted toward the wrong sector, a result multiple accounts credit at least partly to the successful misdirection of Ottoman and German command attention toward Gaza, opening the path for the subsequent capture of Jerusalem later that year.