If Germany statys neutral, the French and Russians meet in Vienna, while their navies remain bottled up in port by the Royal Navy. Also probably a major North African front centered on Italian Libya - if the Royal Navy can secure control of the Mediterranean I imagine it being a focus for Indian/ANZAC forces, plus what can be shipped to mainland Italy. It just a case of how long it takes an undistracted French Army to break through into the Po Valley and an undistracted Russian Army plows into Galicia and possibly over the Carpathians.
Austria-Hungary implodes as Serbian, Russian and eventually French soldiers march deep in country. Austria, Czechia with a Russian king, a stunted Hungary (possibly including Slovakia), Yugoslavia taking much of the southern land, Galicia-Lodomeria annexed by Russia. Italy is unlikely to see major territorial changes bar some land lost to Yugoslavia but she'll be stripped of her colonies and much of her fleet I imagine, if Italy is truly crushed by the French. Depending of the situation on the ground Libya, Eritrea and Somalia could end up in British or French possession. I imagine the Franco-Russian forces could crush Italy and Austria before a sizeable British army can march through into Tunisia and Algeria but perhaps Tunis is given more neutral, independent status alongside Libya as an isolated but unbeatten Britain attempts to get concesssions in partially accepting Franco-Russian pre-eminence, though London will certainly be courting Berlin quick sharp.
But in most realistic scenarios, Germany is picking a side and its unlikely to be with France. So its WW1 with Britain joining, and Italy sticking with, the Central Powers. If France holds on and we see longer term trench warfare, USW is a non-issue so no likely US aid even if it could get across the Atlantic in the face of the Royal and German Navies.