Thanks for the info.
Wikipedia has the following sourced info which shows how large the British forces in Belize were in 1989:
British Army Forces in Belize- 1st Battalion, Welsh Guards, on six month roulement.
- 1 x Armoured Reconnaissance Troop, six month roulement.
- 1 x Field Battery, Royal Artillery, six month roulement.
- 1 x Field Squadron, Royal Engineers, six month roulement.
- 24th Squadron, Royal Corps of Transport.
- 78th Ordnance Company, Royal Army Ordnance Corps.
- No. 25 Flight, Army Air Corps.
Royal Navy Forces – Belize:- West Indies Guard Ship, as needed.
Royal Air Force – Belize:- No. 1417 Flight RAF
- No. 1563 Flight RAF
- 1 Air Defence Flight, RAF Regiment, six month roulement.
Source: Ivelaw Lloyd, Griffith (1993). The Quest for Security in the Caribbean
That is quite a lot of troops.