Just recently, I have been told the following:

1. Intelligence Allies only help defensively, not offensively.
2. Spy tech only works offensively, not defensively.

I don't believe either of the above are true and the in-game descriptions don't imply either of them. But perhaps the in-game descriptions (Research -> Helpful info on techs and Relations -> Helpful info on allies) could be more explicit or descriptive?

For reference...

IA description in-game:

An intelligence alliance brings together the strength of each member's intelligence agencies in both engaging in and protecting from spy operations. This alliance consumes 0.15% of your networth to maintain.

Spy Tech description in-game:

Researching better intelligence strategies and developing better survelliance equipment allows you to improve the effectiveness of your intelligence agents, allowing you to keep a smaller spy force and achieve the same results.

spy ally should work offensively too, otherwise its not that useful.

afaik spy ally works defensively and offensively
as does the tech.

Spy Allies & Tech help both offensively and defensively! (And yes I just looked that up to be sure ;)