It's a well documented fact that during Project MKUltra the CIA was beginning to crack through the window of time and were taking baby steps in traveling to and fro. Now, nobody can speak towards the constituent tests or results of Projects MKDelta and MKNaomi, but it's just naive to think that they didn't drive that nail all the way down to the track the very instant they had the direction and funding to do so, which they most certainly did. This kind of technology would never be destroyed, only buried, especially by an organization so dedicated to documenting as much as possible regarding scientific and political advancement.

So I propose that They, in the interest of saving the world if only to use it for more illegal and amoral tests, provide a particular piece of technology to a particular man to influence 3 key points in history to undo most of the problems currently present in the world as we know it.

Secretary of Defense James N. Mattis is, as we all know, one of the greatest martial minds to ever grace this earth, past, present, or future (which They can confirm objectively). His unmatched abilities as a leader of men and tactician can, without a shadow of a doubt, with the appropriate means, be placed in a few specific times and places to exceptional and globally beneficial effect, which are as follows;

1. Ethiopia, 1934 - Giving him upwards of a year to organize the Ethiopian military against Italian invasion, if not resulting in an outright victory, then holding out long enough to either join or be supported (directly or indirectly) by the Allies, would mean Ethiopia would have the international influence and raw power to stay an independent political presence in the continent. This would make them a perceived threat to nearby muslim states, likely primarily Egypt and Iran, which would not only take some degree of pressure off Israel, but pressure Ethiopia into developing quickly and self-sufficiently both economically and militarily, potentially opening a doorway for nearby Christian nations to do the same. Eritrea would be thoroughly stunted, potentially even prevented outright from turning into the dictatorship it is now, and Somalia would have political pressure on its' land borders, meaning Ethiopia's hypothetical new peacekeeping or isolationist diplomacy roles and actions could lever against them to reduce some of their fuckery (in particular, likely reduce piracy by a dramatic amount in the adjacent seas).

2. The Russian Empire, 1917 - The White Army was not doing well at all by the time the Bolshevik menace decided to revolt, but considering how nearly they held on, it's well inside reason that with a man such as James Mattis would be enough force on their side to pull through. With communism failing during one of its' most violent attempts, it would never get a solid grasp on this planet of ours, and spiral into a golden age for many countries adversely affected (AKA all that were affected) by its' decaying and corrupting phalanges. China would have one less reason to split into more pieces, thus being at least partially readier to stand against the Japanese invasion, and while that would almost assuredly do little to impact the result of the war between the two, it would make it a slower, more costly conflict for Hirohito, potentially ringing in a faster Allied victory in the Pacific upon the US' involvement. And, of course, China would no longer be at incredible risk of devolving into a corrupt dictatorship (more like a misguided one at worst), which has an extensive laundry list of benefits for the world I don't dare try to list for the sake of brevity. Additionally, communist revolutionaries around the world would no longer have any power but their own, seeing as the one superpower they could look up to would be erased from existence. This would have the added benefit of likely preventing Haile Selassie's murder in the '70s by communists, leading to additional stability and international influence on the part of Ethiopia, as well as hindering the spread of Islam.

Even failing to lead the White Army to victory, the mere act of shattering Red Army forces at the battle of Tsaritsyn alone would completely undermine Stalin, killing the respect and trust of his peers for good. While not destroying communism, it would remove the possibility of that sociopath from leading the Soviet Union, most probably resulting in a significantly lower body count. And, unfortunately, a more tolerant public perception of communism.

3. Constantinople, 1096 - Just in time to organize, train, and lead Byzantine forces against the Seljuks to supplement the Komnenian deathball in causing as much damage as possible to the Turkic military and power, whilst increasing the amount of land taken and held, likely as well as for how long. I don't think this one really needs in-depth explanation.

Gina Haspel, I really don't want to know how you got this technology or what you've done with it. All I know is it can be put to use to save the world from some of the greatest injustices and threats history has seen. Send that SECDEF straight to the past.