The Klingon High Council feared that Starfleet was developing armies of Augments; after gaining access to genetic material from the Augments, the Klingons performed experiments to increase their own intellect and strength.
Starfleet was developing armies of Augments. The Klingon High Council feared this. The Klingons performed experiments. This was to increase their own intellect and strength. The Klingons were gaining access to genetic material from the Augments.