Harry's act of giving up the Albany file at the end of season 9 of Spooks (MI-5) is powerful and significant and does prove his love for Ruth, even though Albany was worthless as a weapon. (Beware of Spoilers for Season 9, episode 8).
If watching this show has taught me anything it is that what people believe to be true should not be underestimated as a political and strategic tool. Almost everyone who knew of its existence, even the very highest ranking officials, believed Albany to be a dangerous blueprint for a sociopathic genetic weapon. That belief was itself a poker chip keeping various world power struggles in check.
In 9.8 when Harry gives up Albany to the Chinese (in order to secure Ruth's release), the reality of what he is handing over is not a weapon but rather, knowledge. He knows that the Chinese will discover that Albany is not a workable plan, and that very real information will change the way it interacts with England and with other countries who know of Albany. (Like in Clue, what your opponent doesn't reveal about her hand is just as valuable as what she does.)
And this twist it is a brilliant ploy by the writers of MI-5 to give Harry a way to prove his love for Ruth without actually needing to decide whether he valued her life more highly than the millions of other lives that would be cruelly and racistly snuffed out if the weapon were real, not to mention allowing us to sidestep the question of whether he would treat her more preciously than all the other agents who have died in the line of duty. And that's good. Because Harry loving her that much would not have made Ruth love him more.
Instead, Harry gets to give up something that might. Just. Something far more personal -- his stability in his career. Because there is no way Harry can come away unblemished from this act. To the extent that the fiction is preserved that Albany is a real genetic weapon, Harry is going to be blamed for handing it over; to the extent that the truth about Albany is exposed, then Harry is responsible for any political or diplomatic fallout that may occur due to that knowledge. Either way, Harry's choice to dredge up Albany and give it to Lucas was Big.
"The Significance of the Albany File to Harry and Ruth." LostinBritishTV