Someone should make a TL out of this. The Song is just way too overlooked in Chinese history.
A POD for a Song Dynasty TL that doesn't lose out to the Mongols. In 1086 Su Shih is brought back from exile and is made the head of recruitment for an intelligence agency that will focus on intelligence gathering and secret operations to disrupt the operations of any threat against China. The agency will have a legal front, called The Office of Map and Travel Studies, under the Bureau of Operations in the Ministry of War. The idea for the agency will come from Su Shih's old political foe Wang An-shih. Su Shih will use his new official job at the Hanlin Academy to sift through applications and government service exam test results to find suitable agents, recruit them, and send them on to the OMTS. From there, they will travel China and nearby nations to collect information that will be sorted into various categories. There will be an "Open" category of useful information that will be shared with other parts of the government, but the really valuable stuff will be collected in secret files that the head of the OMTS will use to formulate secret policies and capabilities for Song as a whole. Areas of involvement will include the following:
1) Foreign penetration - Uncovering and eliminating persons who are operating in Song on behalf of foreign governments, including foreign agents, native dupes, native private traitors, and native traitors inside the military or the government.
2) Field studies - Assessing geography for weak spots in infrastructure and general layout of the land that would aid a foreign invasion.
3) New capabilties - Funding, developing, and creating advanced weapons and making them available to patriotic officers of the army and navy when the timing and opportunity are correct.
4) Foreign Policy reporting - Gathering as much information as possible from inside foreign governments and military camps.
5) Foreign Policy Projection - Disrupting hostile foreign action before it becomes a serious threat to Song, such as killing especially hostile and competent foreign military officers and ideally getting them replaced by idiots or traitors or even assaulting whole military units in camp or on leave with fire, poison, or infectious diseases.
The money for all this activity will be provided by a patriotic group of private citizens and will be funneled to a secret budget accessible only by the head of the OMTS, referred to as "The Mapmaker." Su Shih's position will be referred to as "The Gatekeeper."
Anybody who wants this, have fun. The Jurchen are coming in 1127.