but there is also no evidence that they are bought abroad
I was responding to an assertive suggestion that Karrar is being produced under licence. So we've established there's no evidence to this effect. Excellent, that's what I was conveying.
But since you commented on the topic, allow me add a final, important point: there
is actually evidence of Karrar being an Iranian development indeed.
To begin with, the tank was revealed at a time when Russia was officially offering Iran a license to produce its T-90S MBT, a rather rare type of proposal by Moscow.
https://thediplomat.com/2016/02/will-iran-license-build-russias-t-90s-main-battle-tank/
So what explains Russia's willingness to offer local production on a rather modern platform at this point in time? Most likely, Russian awareness of the progress made by Islamic Iran in upgrading and modernizing the T-72.
This is strongly reminiscent of MAPNA's successful reverse engineering and manufacturing of a Siemens gas turbine, which left international observers awestruck and immediately prompted the German corporation to offer Iran license production for gas turbines from its own catalogue, in hopes of securing at least a share of the profits on Iranian-made devices of this kind.
Secondly, Iran's Brigadier General Ahmad Reza Pourdastan put to rest speculation about the origin of technologies used in Karrar by highligting that it's a domestic achievement and that as a result of it, Iran lost the interest she once had in purchasing Russian tanks.
“
We were once interested in buying the Russian tanks,” Brig. Gen. Ahmad Reza Pourdastan, the Iranian army’s ground forces chief, told the Fars News Agency in February. “But since we can manufacture similar models within the country and we plan to do so in the near future, the deal is now off.”
https://nationalinterest.org/blog/t...k-one-the-most-advanced-tanks-the-world-17468
Please take note.
Conclusion: Karrar is an indigenous effort. Quod erat demonstrandum.