Some grammar hints.

[AUTOMOON]

It was about this time that the conflicts between the two countries was over.

Why not " at this time"?

[Tdol]

It's less precise- it might have been slightly before or after. BTW, it should either be conflict....was or conflicts...were. Of the two, I'd go for the singular without further context.

[AUTOMOON]

Okay, but what about " at about this time?"

[Casiopea]

Okay, but what about " at about this time?"

In addition to tdol's reply, with which I agree, :D , what about?

It was around this time. (near)
It was at this time. (exact point)
It was at about this time. (near the exact point)

All the best,