At Westminster Magistrates' Court on Thursday, Y also pleaded guilty to having cannabis on 30 November 2023 with intent to supply, while X admitted being in possession of the drug on the same date.
Defendant X also pleaded guilty in court to possessing articles for use in fraud, relating to seven receipts for a Rolex Oyster Perpetual 41MM Jubilee watch.
Identified only as X and Y, the defendants pleaded guilty to being concerned in the making of an offer to supply the class B drug between 23 November and 28 November 2023.
Mr Hookway then told the court the pair exchanged messages discussing selling the cannabis and spoke of selling 2.3kg for £8,750.
The Armed Forces members, who are involved in "kinetic operations", will be sentenced at Westminster Magistrates' Court at a later date.
