Bio-warfare In Middle-earth

[Inziladun]

I started thinking about this after re-reading ROTK Appendix A.

"Ever will some new evil be hatched in Angband beyond the guess of Elves and Men," they said. And in the autumn of that year, to point their words, there came an ill wind from the North under leaden skies. The Evil Breath it was called, for it was pestilent; and many sickened and died in the fall of the year in the northern lands....

UT Narn I Hîn Húrin

Soon after a deadly plague came with dark winds out of the East. The King and all his chidren died, and great numbers of the people of Gondor....for weariness and fewness of men the watch on the borders of Mordor ceased...Later it was noted that these things happened even as the Shador grew deep in Greenwood, and many evil things reappeared, signs of the arising of Sauron. It is true that the enemies of Gondor also suffered, or they might have overwhelmed it in its weakness; but Sauron could wait, and it may well be that the opening of Mordor was what he chiefly desired.

ROTK Appendix A

Two epidemics of deadly disease, each apparently deliberately introduced.
The first, Morgoth's seems to mainly have been a terror weapon intended to weaken the will of the Men of Dor-lómin prior to the Nirnaeth, as it had an especially terrible effect on their children.
Sauron's use of the plague was more tactical: he wanted to re-occupy Mordor, and could not do so while it was constantly guarded by Gondor.

Here's the issue: the use of plagues could have brought great mortality to Sauron's foes in the years leading up to the War of the Ring, or during the War itself. Certainly his own armies would likely be affected, but still: it seems to me the sacrifice might have been worth it.
Why didn't Sauron attempt to set another plague on the West after his return to Mordor?

[alatar]

Originally Posted by Inziladun

Why didn't Sauron attempt to set another plague on the West after his return to Mordor?

Good question. It may have been simply ROI - return on investment. We don't know what it took for Sauron to cook these things up. He may have thought that, with the poisoning of Denethor's mind and the alliance with Saruman the traitor that there was no need to send another plague. He may also have been 'employing' more human types, and so his losses may have been greater than in the past. Think about the new creatures that didn't blanche at the sunlight.

And take it from me, you can only spend so much time in the lab.

[Ibrîniðilpathânezel]

I think it's also possible that he didn't do it again because he had achieved one of the goals of sending out a plague: he had diminished the numbers of his foes to the point that the various groups were effectively isolated from one another. Such separation tends to keep people thinking more about themselves and less about others, so that when the time comes to band together against a common enemy, they don't want to, either because they've grown suspicious of outsiders, or because they feel that they barely have the numbers to defend themselves, and not enough to send help elsewhere. Had Gandalf not intervened in Rohan, that end would have been achieved.

[alatar]

The other goal may have been to taint/dilute/counteract the Númenórean blood. Think of the plague as an anti-elven marriage. Instead of living hundreds of years, being healthy, going on strong until the very last, being far sighted, the plague brought us all down to where we are today.

[Bêthberry]

Another thing to consider: plagues are not specifically designed weapons. They target everyone. And that would possibly include the Ring Bearer. It it had been buried with the Bearer, the Ring could have been lost in a grave with a little quick lime or, if he fell far away from civilization, in some unknown clime, blanketed by leaves and earth and perhaps prey to carrion-seeking carnivores. Like the River, the earth would give the Ring a quiet bearth where none would find it. Until upheaval, of course. And that possibility may be a little too long term even for someone with eons of time at his disposal.

[alatar]

Originally Posted by Bêthberry

Another thing to consider: plagues are not specifically designed weapons.

But they could be...

It it had been buried with the Bearer, the Ring could have been lost in a grave with a little quick lime or, if he fell far away from civilization, in some unknown clime, blanketed by leaves and earth and perhaps prey to carrion-seeking carnivores. Like the River, the earth would give the Ring a quiet bearth where none would find it. Until upheaval, of course. And that possibility may be a little too long term even for someone with eons of time at his disposal.

Nice exegesis (for lack of a better word as my 'common tongue' thesaurus in my head in on the fritz). I think Sauron was getting tired of waiting - he'd spent more than a few years waiting up at his summer home - and so was looking for a more decisive end. As stated, he already had a plan for Rohan, and Minas Tirith was being neutralized, and so there wasn't that much more to do...

..except to pick out his victory wardrobe.