Even civilian radars have an SSR (monopulse) capability out to 200nm +, Primary radar up to 100nm. In a military environment with ground based Air Defense radar I am sure in the new world of technology, they will have quite impressive performance that may exceed this.
Stand off assets, like AWACS for example, are often squawking as they may be in adjacent airspace which may not necessarily be military controlled, so they will be displayed quite openly on a civilian based radar syetem (as was the case in this theatre) and therefore be readily observed by enemy based systems.
This exposure or vulnerability to ground based and/or air threats would be removed or supressed at the earlier phase of an operation to allow these components to move into the closer operating ranges necessary conduct the specialist tasks required.