Without the British, and with America's aloofness to the troubles of Europe, I find it difficult to believe that France could survive long enough by itself on the Western Front for some German-instigated incident to push America into the Great War. Maybe if you had Teddy Roosevelt get his third term, and some Wilhelm II-instigated diplomatic incidents in the lead up to 1914 severely souring relations with the USA, then maybe TR would be willing to go riding to the rescue of their old allies France and Russia.
The British would be just as well pleased to have American soldiers bleeding in the Western Front's trenches while they loan money and export weapons and supplies to France and Russia, perhaps eyeing for an opportune moment to enter the war to snatch some German colonies. Interestingly, this would mean Japan would also be neutral in the war, as the Anglo-Japanese Alliance hasn't been activated, so the German Pacific colonies would only have to worry about the French fleet based in Indochina - until America enters the war and they have to worry about the US Asiatic Fleet based in the Philippines.
If you look at the Twenty-One Demands issued by Japan to the Republic of China in 1915 IOTL though, would Britain's neutrality in the conflict necessarily be enough to ensure Japan would stay out of the conflict as well? Even more so, given that any renewal of the Anglo-Japanese Alliance as happened in 1911 IOTL would be entirely different in such a TL: when OTL's Anglo-Japanese alliance was reoriented due to the Anglo-Russian entente of 1907 having settled the Russo-British 'Great Game', Japan's victory in the Russo-Japanese War and their own 1907 agreement to partition Manchuria with Russia; increasing British-American rapprochement, and the UK's growing rivalry with the German Empire instead.
If the British Empire are remaining gloriously apart and unconcerned from WW1, then it can only be because they're not aligned with either side in the conflict. And in such a TL, the Anglo-Japanese Alliance would've never been renewed in the manner it was IOTL, and may well never have been established at all. After all, it was the Anglo-Japanese Alliance which effectively brought an end to Britain's "splendid isolation" IOTL, as for the first time Britain saw the need for a peace-time military alliance, and followed it up with the Entente Cordiale (1904) with France and the Anglo-Russian Convention of 1907. And if Britain's still sticking with 'splendid isolation' through WW2, then such a Britain would've almost certainly never forged that alliance with Japan to begin with.
Which in turn could've well led to some out-of-left field alignments for TTL's WW1 (which almost certainly wouldn't have been 1914-18 ITTL). Let's not forget that during the build up to the Russo-Japanese War of 1904-05, Kaiser Wilhelm II of Germany had sought to actively provoke conflict in the Far East in order to further his own goals within Europe, hoping that having Russia pursue an expansionist policy in Asia would distract and keep Russia out of the Balkans, thus removing the main source of tension between Russia and Germany's ally Austria-Hungary; whilst also further estranging Russia from its French ally, which in turn wanted Russia to limit its eastern expansion and recommended a diplomatic solution to its territorial disputes with Japan.
To this end, the Kaiser and the German government embarked upon a fervent and dedicated “Yellow Peril” campaign, intending to turn both Germany and Russia’s populations against Asia while improving perceptions of each other. Kaiser Wilhelm II repeatedly attempted to push Tsar Nicholas to go to war with Japan, going so far as to call him a coward when the Tsar seemed a bit willing to seek a compromise with Japan. Russia likewise suffered from over-confidence due to German assurances that they'd come to Russia's assistance, and the racist belief that the Japanese or any Asian power could never defeat any allegedly “superior” European power.
The Kaiser’s governmental support invigorated the Russian public, who believed that despite a relative weakness in Russia’s east, with no trans-Siberian railway or other means of supply, they would be able to crush the Japanese Empire either alone through their own superiority or with the help of their “White brothers in arms.” Soon enough, it became clear to Japan that the Russians were now only working in bad faith and had no genuine interest in diplomatic resolutions to Korea or Manchuria, instead stalling as more Russian forces were transferred to the Far East, and Japan declared war themselves, preceded by a surprise attack by the Japanese Imperial Navy against the Russian Far East Fleet anchored in Port Arthur.
Several victories in Manchuria and Russia-occupied China led the Japanese to believed that they would achieve some form of negotiated settlement from the Russians, but the Tsar refused to accept that his “Glorious White Russia” could be brought down by a regional Asian power and would not even consider the humiliating possibility of a peace settlement, still clinging to the hope of Germany intervening on Russia's behalf. But while they remained publicly and politically supportive of the Russian side, Germany flaked out; since the British had refused to aid the Japanese, but had still agreed to join the war on Japan's side if any European power besides Russia were to intervene. And it was because of the Anglo-Japanese Alliance that OTL's Russo-Japanese War remained a contest between two nations, with no outside intervention.
ITTL though, with a 'Splendid Isolation' Britain staying that way, there'd be no Anglo-Japanese Alliance. No Entente, no Anglo-Russian Convention. And nothing to stop Germany from providing the Russians with support in the Russo-Japanese War as they'd promised. Though it'd still be highly questionable whether the German Empire would be able, or willing, to provide the Russians with enough support to actually win. If this war does still end as and when it did IOTL, and Imperial Japan still achieves the naval victories they did IOTL, it'd be plenty plausible for the Japanese to wind up more closely aligned with France and/or the USA than they are with the British in its aftermath. And if it doesn't, there's plenty of possibility for the conflict to spiral into TTL's equivalent of WW2 (in the same sense that the Marco Polo Bridge Incident could be said to have spiralled into WW2)...