What happens to a research agreement when we go to war in Civ 5?

I formed a research agreement with an AI in Civ 5, and when it was about halfway done he attacked me. Is that money just gone for both of us, or can we resume it somehow once I've taught him a lesson?

Solution 1:

Investments into Research Agreements, if broken, are lost. This is why you should never go to war with your research partners if you can help it -- since you both lose.

Solution 2:

The money you each put into the agreement is lost. This is not necessarily a bad thing - if you can trick someone into a research agreement before going to war, they will lose that money, which they could have used on defending themselves.

According to Wikipedia, the higher-level computer opponents will sometimes use this strategy.