Indeed.All Russian could was send some cossack,and what they would achieve there ? It would worked only if local rulers joined them.
Not by 1904-1907 she wasn’t.
Germany never posed a threat to Britain’s homeland, much less her colonies. France and Russia however did pose a direct threat to British colonies.
The British knew this policy was untenable by 1914. This is why she backed Russia and France over the Central Powers, although those two sides were already equal: better to be allied with your biggest threats for that way they can be occupied with other powers. Had the British backed the Germans, there is not much the British could have done to help the war effort other than blockade Russia and France. This would not have prevented the French and Russians from steamrolling into Germany and leaving Britain isolated like in the Napoleonic Wars. I’m not saying this WOULD have happened, rather it was the thinning of the time.
WWI would refute your argument. It took all three great powers and then the addition of resources from the US to defeat Germany and its allies. True the allies made a lot of mistakes and with better decision making or some luck could have done it earlier but it would have still been a tough fight.
On the other hand an Anglo-Germany alliance, while not strong enough to easily defeat an Franco-Russian one, would probably have deterred the latter from any attack. Britain can supply a hell of a lot of industrial, fiscal and naval power without which neither France nor Russia could have fought a long war, let alone the military strength it could build up over time.
It is true that its often stated that the German army feared that by 1916 they would be incapable of defeating France quickly by a sudden attack in time to turn against Russia before its fully moblised. Which might be a factor in why Germany seemed to eager for war in 1914? However an Anglo-Germany-Austrian bloc would have been a totally different factor. Or even a neutral but pro-German Britain provided that Germany was prepared to take a defensive stance.
However the German decision to take a deeply hostile stance to Britain made this impossible. A powerful fleet backed by the German army was a direct potential threat to Britain even without the continued hostile references by German leaders. It forced the redeployment of most of the RN capital ships to the N Sea to cover against such a threat. Prior to this the top priority force for the RN was actually the fleet in the Med because of Britain's interests there and its importance for the direct route to India and Britain also retained smaller fleets of capital ships in many other areas. Britain had to make strategic decisions that weakened its influence in many areas to respond to the German threat.