What makes me think that? Public acknowledgement of RN submarines being involved in:
Gulf 1991, two old O class diesel subs were involved in operations. Reece, possibly some SF type stuff.
Adriatic 90s, Operation Sharp Guard involved RN submarines, after the operation ceased this was acknowleged.
Kosovo 1997, reece and ELINT type stuff and first use of Tomahawk by non US forces.
Afgahnistan 2001, UK boats fired Tomahawks at Taliban targets, and perform other roles.
Iraq 2003, UK boats fire Tomahawk at regime targets, and perform other roles.
War on terror (ongoing), submarines perform ISTAR and other roles.