That research budgets are split by subjects many times before arriving to a node where "string theory" is a possible leaf is not a controversial statement, it is reflected in basically all budget documents you will find.
For example, string theory funded by the NSF that "steals" money from laser research is plausibly only found in the "elementary particle physics - theory" program, which is part of the Physics division, which is part of the Mathematical and Physical Sciences Directorate.
sadly the page is pretty shit so the filter selection is probably reset, and they don't label by division program so you'll have to mouse over each one and categorise yourself. As a guide to how much work it is, there was 350 awards in the physics division and about 30 of those in the theory program.
For example, string theory funded by the NSF that "steals" money from laser research is plausibly only found in the "elementary particle physics - theory" program, which is part of the Physics division, which is part of the Mathematical and Physical Sciences Directorate.
You can find all NFS awards in the physics division, so about one step above where string theory could plausibly show up here: https://tableau.external.nsf.gov/views/NSFbyNumbers/Details?...
sadly the page is pretty shit so the filter selection is probably reset, and they don't label by division program so you'll have to mouse over each one and categorise yourself. As a guide to how much work it is, there was 350 awards in the physics division and about 30 of those in the theory program.