The eternal theme of this world is only — interests. With severe conflicts of interest between England and France, and without sufficient external pressure, it's naturally impossible for them to truly unite.
In the original time-space of the German Second Empire, the French were under such great pressure that the Paris Government would rather go to great lengths to woo the Russians, rather than approaching the British first, which is enough to illustrate the problem.
After the Franco-Prussian War, the Germans and the British both became the greatest enemies of France, and in the following decades, England and France nearly went to war several times.
The reason why the Franco-German conflict surpassed the Anglo-French conflict was still Wilhelm II's death-wish behavior, repeatedly provoking the national sentiments of the French, and being exploited by the British.
