Halliday & Matthiessen (2014: 582, 582n):
Only one or two modulations have causative equivalents; e.g.John remembered to do it
(caus.) Mary reminded John to do it
with the sense of ‘John did it according to attention’ and ‘Mary caused John to do it according to attention’. However, there is a special set that exist only as causatives, where the meaning is simply that of agency: make, cause, force, require, let, allow, permit, etc. These admit of three degrees of modulation:
(high:) this made (forced, required) them (to) accept our terms
(median:) this had (got, obliged) them (to) accept our terms⁶
(low:) this let (allowed, permitted) them (to) accept our terms
The concept of agency is inherently a circumstantial one. We have already seen in Chapter 5 that the Agent, which from one point of view is a participant in the clause (John did it), is from another point of view a kind of Manner (it was done by John). It is thus not surprising that the causative Agent enters into this kind of hypotactic structure, with the agency expressed as a process through verbs like force and allow.
⁶ Also imperfective: got them working, had him begging for mercy.