The army is worried about what the FARC has learned
The three suspected IRA men arrested in Colombia have knowledge that could change the face of this country's 37-year civil conflict.
The three men, David Bracken, James Monaghan and Martin McCauley are believed to be part of the Provisional IRA's Engineering Unit, experts in the design and construction of explosive devices and home-made mortars and rockets.
They spent five weeks with the Revolutionary Armed Forces of Colombia (FARC).
With more than 18,000 fighters, this is the country's most powerful rebel army, controlling almost 40% of Colombia.
Key weaknesses
But it has two key weaknesses. It is a rural fighting force with little urban experience, and its knowledge of explosives is primitive.
These are two areas in which the IRA excels.
The FARC field marshal Jorge Briceno, better known by his alias 'El Mono Jojoy', has admitted it has problems with the use of home-made mortars, constructed out of gas cylinders used for cooking, a common feature in Colombian kitchens.
Almost every week the FARC attack some isolated outpost of the security forces, pounding bases with these cylinder bombs.
But the collateral damage is huge, and often more civilians are killed than security force members.
"We have made mistakes with the rudimentary nature of our weapons and injustices against our own people, so we are analysing other possibilities," Mr Briceno said.
In July he announced the FARC would be taking their fight into the cities, largely isolated from the fighting until now.
Army claims
The Colombian attorney-general's office stated that traces of four different types of explosive were found on the Irishmen's clothing and in their luggage, lending credence to army claims it has evidence the IRA men were training guerrillas.
It remains to be seen what the Colombian authorities are going to do with the three men.
If no extradition requests are forthcoming from Britain, Colombia has two options: to deport the men or prosecute them for entering the country illegally and training for terrorist purposes.
Legal sources indicate the latter is more likely if a case can be built, as the security forces are afraid of what these men have taught the FARC. Very afraid.