The name space for the domain below strategic nuclear and conventional warfare is a mess, and we aren’t going to clean it up here. There is considerable overlap in the taxonomy shown below. Some are overt and some covert; the formal distinction between covert and clandestine isn’t always honored.
Those forms of overt warfare involving armed conflict other than state-on-state warfare—conventional and strategic nuclear warfare—are lumped together here under the rubric of low-intensity conflict. html
Covert operations may involve military force, but some may be purely informational or economic. Some LIC operations are covert, e.g., unconventional warfare is a mission assigned to special operations forces; it would be more clearly labeled proinsurgency or war by proxy. html
In the early days of the Cold War, psychological warfare and psychological operations were largely a matter of communications and messaging. More recently one hears of influence operations or strategic communications. Messaging, unfortunately, is often too from removed physical action. html
In old policy statements, psychological warfare and political warfare are often used as near synonyms. It has evolved into something more expansive. html