The OED finds 1225 as the earliest use of "dispute" (in the form "disputing") to mean debate, perhaps heatedly. This is an intransitive use, with the topic of the debate consigned to the object of a preposition ("against," "on," "upon," etc.) By 1340, the topic has migrated to a direct object, and the verb has become transitive, as in:
How long can they dispute the boundary separating their properties?
About two hundred more years, and the word takes on the connotation of a particular kind of dispute, one that questions the validity of the other side's argument for something or even the existence of that thing. For the latter, the OED quotes DeFoe:
As to Vices, who can dispute our Intemperance?
In the example, "aggressive interrogation techniques for military intelligence" is a euphemism for torturing prisoners of war. The policy debate is a dispute in both senses of the word. First, it is certainly a heated topic of debate. Secondly, the pro-torture side has both denied that the techniques were torture and also claimed that the torture was justified for "military intelligence." The other side has controverted these claims, arguing that torture took place and was unjustifiable.