Someone cruise missiled me early in the set when i had 0 military and forgot GDI.

I promptly joined GDI and then they DHd me with their all tank/troop combo. I grabbed them back and got a message saying "you can't retal a DH", then they DHd me again...

If I hit him back again do I break GDI?
I feel like I'm being trolled and he wants me to break it so he can just AB the hell out of me.

Thanks

And if I do break GDI... what stops someone going all tanks and just feeding off the same person multiple times, tempting them to retal twice, break GDI and get flattened?

Yes, if you hit again it will break GDI. Right now you're safe from all except the normal attacks/ops.

What stops that person in your hypothetical, aside from most people aren't trolls like that, is that you can get first strike once they hit you more than once, and you can crush them first. If they're all tanks, use bombing runs.

Well #125 is trolling me *sigh*.
Guess I should start using the same name every set, because wasting my set to kill him doesn't really help me given that next set my name will be different.

Your post was a bit confusing but ill explain how GDI works on EXPRESS fou you.

GDI v. Non-GDI
Non-GDI v. GDI
GDI v. GDI

All 3 of the above have restrictions as to which types of attacks they may do to another country.
They are limited to SS / PS / spy ops Intel / bomb banks / burn food.

However, if country A attacks country B more than ONCE during that set, then country B may attack country A with any sort of attack.

Retals are irrelevant. The formula is simply if you attack more than ONCE then you're no longer protected by GDI from that country.

If someone attacks you more than once, you have the option to go all out assault on them whenever you want. Or you can just retal once and ignore their future attacks. This is why some players prefer to play Tyranny so as to kill any country who attack them twice.

From what I see,.. you're x2 his net and you defended against all his attacks. I wouldn't even worry about him. If anything, he's helping you by raising your DR.

The fact that he's DH'd every attempt makes me think it's a troll.
I've lost over 100k turrets every attack while he only loses ~30k tanks.

If he continues that every 2 hours... I'm losing a ton of money lol

Yes, but you're gaining DR without losing land. Which makes you less of a target from countries who would land a successful attack.