There's nothing of the sort. Japan had, at that point, acquired everything they needed (German ports in China and the Pacific) and their attempts to force China under their wing was thwarted by numerous conference and by China simply joining the Allies.

As for everyone else there is absolutely no textual evidence to support this. American Generals did not have control over French & British armies (they did not have 'the supreme commander' title or anything like it) so I don't know how you'd convince me that they somehow influenced the Brits and French, whose economy was obliterated by this war, to continue the war. These are called conspiracy theories for a reason -- there is nothing backing them up. It's people who look at high death tolls and think, golly that's a shitty situation it must be some government cabal trying to profit off of it. It's trying to force the war into their narrow, deterministic worldview.

Generals wanted to win the war. The battles they embarked on were to win the war and made great progress toward doing that at least for the Allied side. As for:

wartime generals to encourage them to continue their "meat grinder" tactics, despite complaints from the civilian leadership

There's reason why civilian leadership complained and wartime leadership did not; because civilians do not understand war. This is what I mean though; the Generals purposefully embark on a strategy of attrition because decisive warfare was a more costly option on the Western Front -- as in they use a strategy specifically designed to lose less lives and to make the Germans lose more over a longer period of time -- but people stop at the 'attrition' part and call it 'stupid' or a conspiracy.

On WWI "stupid tactics" and "the meatgrinder", etc. and why it's a bunch of baloney I'd suggest:

• In World War I, why would a General ever order his men to attack an enemy trench? Why not sit back on perpetual defense, eventually having millions of extra men due to an excellent casualty ratio?

• World War One - Stupid Tactics.

• How did World War One trench fighting work? What was it like?

The amazing thing, at least to me, about my study into the First World War was how quickly my entire worldview changed once I actually began to read scholarship on the topic. One of the greatest pervasive myths about WW1 is that it was especially deadly and that the tactics were stupid and Generals had no idea what they were doing. The tactics were not stupid nor was the strategy. The British had to attack because if the Germans were allowed to they could break through in the Somme region and separate the Brits and French and further encircle all the Brits in North France. See this picture for what I mean.

The tactics were not static and in fact those images you have of blobs of infantry running in blobs into enemy trenches was really only true for like...1915 and some of 1916. Strategy and tactics changed rapidly on the front as I go into great depth here. In my opinion the very application of what is 1917 and especially 1918 warfare takes a dump all over this point. The claim is that America somehow extended the war artificially by making people keep using 'meat grinder tactics' even though 1918 is most known for its radical use of almost WW2 looking tactics is just bonkers to me. Infiltrating squad based tactics, combined arms assaults, hurricane barrages rather than week long bombardments, the platoon being turned into the smallest tactical unit rather than the company (~60 vs ~250), aerial reconnaissance and bombing, flamethrower and grenade focused warfare with lighter platoon based machine guns and personal mortars, armored protection and assaults (though this part is certainly overstated at times), and so on and so on. These were all mid to late '17 and '18 innovations used by everyone on the Western Front; this type of tactical and doctrinal upheaval does not align with the claim that they were 'convinced to keep using meat grinder tactics'.

This claim about it being especially deadly though also comes with the implication that:

1. It actually happened on a significant scale

2. It was a unique event

But we know from demographics that for countries like Britain and France it's almost like the war didn't even happen. France had a higher birthrate coming out of the war than before and Germany about the same with its gradual pre-war decrease. As has been stated numerous times before by others on this board, if you look at the 1.2 million French deaths in the war w.r.t. a census before the war, during, and after, there is little evidence the war even took place. To quote another user, /u/NMW,

"For all that we speak of "a lost generation", the numbers bear out a far different picture -- a picture in which the war more or less supplanted the expected mortality of the period in terms of cause rather than in terms of actual amount."

As for two, as described by John Caldwell in “Social Upheaval and Fertility Decline", similar population rate dips like in WWI had occurred at least 13 other times in history before or since. In other words, the loss of births to this scale as a result of war described by Guillaume Vandenbroucke was not a unique phenomena.

Want to know why the war dragged on? Because Germany thought they could still win. After the crushing defeats at the Somme and the failure at Verdun the Western Front was a lost cause for Germany. They retreated to the newly created Hindenburg Line, cut all offensive operations, and basically threw all their weight into the East to mop that up. With the February Revolution and the October Revolution in 1917 the offensive in the East was almost a shoe-in for victory -- they just needed to hold off the West and wait and deliver that final blow. They had conquered a considerable amount of land by the time the treaty was signed.

With the East under wraps they could throw all their weight West for their final push -- the Spring Offensives. They could not win a protracted war with France & Britain alone let alone America coming into the field so they threw all they had, their most experienced men at that, into these offensives to try and seize Paris and encircle the British. Neither happened and all they succeeded at was throwing their most experienced men away in a costly offensive for strategically unimportant land in undefended areas which were mostly undefended for a reason. It was at this point all that was required was one final push from the Allies to break the Germans back and that was the Hundred Days Offensive which brought about their end.

So the war dragged on not because of some Allied conspiracy to make it go on longer. The Americans did not have that kind of influence over the French & British military's and, frankly, nobody gave a shit about Japan. The war dragged on because their opponent didn't give up; they were winning in the East and felt they could win a one-front war with the Allies in a last ditch offensive using every last man they had left. It was only when that offensive failed and Germany was truly without hope that they surrendered.