CP victory highly unlikely
Given the post that the US does not enter the War, then the CP fate is probably sealed, just on more ameliorable terms.
The allies will still win probably, Summer or early Fall 1919 latest, the CP will offer a conditional surrender that the Allies will accept ( No prospect of fresh American troops means that they do not have the luxury of pushing the CP too far with terms that they cannot accept, because of their own War Fatigue).
Both sides by 1917 are suffering from War Fatigue. But shortages of Agricultural and industrial War materials will no doubt make themselves manifest in the economies of the CP first because of the Wartime Blockade imposed by the Western Seapowers. Even with Brest - Litovsk those resources cannot save the CP from Civil unrest due to severe shortages in these sectors. Resources from the East will not make themselves felt in the economies of the CP until 1920 or 21 at the earliest. With Food riots and labour unrest in the cities of Germany and A-H more troops will be needed simply to maintain the peace of the Empire rather than continuing the fight against the Western Allies. Even if still occupying parts of France or Bel/Lux. The CP will evacuate at the request of the Allies if it brings peace and a chance to secure their own increasingly restive backyards.
The allies , while suffering from War fatigue do not have the associated problems with material shortages. Even if the US does not enter the War..they will still send grain and war materials and vital financial capital to finance the Western War effort. There is not likely to be any unrest in France or Italy. The problems resulting in the French military mutinies have essentially been addressed. While the French troops may have been distressed by the appalling leadership and planning of some of the military offensives...they were commited to defending France itself and ejecting the Germans from all of France. The same will hold with the Italians.
Probable results....
France obtains Alsace and Lorraine. Occupation of the Saar and moderate reparations paid by Germany to compensate for the widespread devastation in Northern France
Germany (if it hasn't been forced out) will evacuate France/Belgium and Lux. to the prewar borders. Smaller reparations to Belgium.
Germany loses its entire Overseas Empire (incl. OstAfrika) in exchange for recognition of Brest-Litovsk. Not highly palatable to the Western Allies, but there will be little they can do about it at this point. Moderate reparations to Britain.
A-H evacuates or is forced out of Italy because of increasing civil unrest and pressure on the Balkan front from the Entente. return to the prewar bondaries. Moderate reparations to Italy in compensation.
Balkan Boundaries are restored, Bosnia-Hercegovina receives its independence but a Yugoslav Kingdom is not in the cards unless A-H collapses sometime after the Peace. B-H, Serbia and Montenegro will have to settle for increasing Economic and Military co-operation instead.
Roumania only gets its gains in Bulgaria and Bessarabia (Moldavia) that it obtained OTL.
The Ottomans suffer the same fare as OTL losing their ME terr. to France and Britain, Italy and Greece. The only difference will be in the details and whether the Porte survives. They may be able to exert some control over the Transcaucasus to compensate for loses in Arabia, Mesopotamia and the Levant. No Armenian republic for instance.
The German Army and Navy survive the War intact ( with no overseas Empire The Navy will be severly curtailed in the aftermath).
Both Kaisers could conceivably survive the War and the peace. If they endure until 1922 then they will probably survive. A-H will have to reform politically to survive intact. Imp. Germany will prop them up in the immediate term, as it is in their interest to do so to consolidate gains in the east via B-L.
IG will have to deal increasingly though with the SDP and their agenda. This should prove palatable to the Western allies through the '20's.
In the West the gains of the allies will seem increasingly phyrric in terms of what was lost for what was gained.. However, French revanchism is satisfied so they will be satisfied in the immediate term. They will however draw closer to Britain as they are still going to be wary of IG and its new Economic hegemony in East Central Europe. This of course is more than balanced by both of them having a mutual fear of the Bolsheviks in Russia.
The course of the Russian Revelution is likely to be entirely different... A "White" victory is increasingly possible and restoration of a Constitutional Tsar along the lines of IG at the very least. The Bolsheviks could very well still win, but their win will be confined to Great Russia only and not the IG and A-H satellites.
In A-H...Galicia will probably still be lost along with Bukovina in the aftermath of the war. It is probably palatable to them even to lose it to a German controlled Polish satellite in exchange for German aid in stabalizing the Empire as it reforms poitically into a more federal state/Empire. A Hapsburg in Poland and a Hohenzollern in a CP controlled Ukraine (This is most likely, though the reverse would probably be better in the long run). Probably Hohenzollerns in the Baltic states or outright annexation there to the German empire. Belorussia another Hohenzollern principality or annexed to Hohenzollern or Hapsburg Poland or the Ukraine.
All the while US financiers loan money to the CP States so they can repay their reparations to the Western allies and rebuild their economies.
If the If the CP empires survive, the chances of a WWII of OTL is increasingly unlikely. If it does occur, it could very well be limited to a Soviet or Tsarist Russian /German conflict instead. Where Imp. Japan would fit is another matter. They will probably not contemplate the move against the European colonies, but could move against Russia instead and curb their activities in China to placate the Americans and avoid the sanctions on War materials. But that is getting too far down the road...