The ultimate roots of the Second Great War lie in the outcome of the First one. That conflict, the first world war of the Industrial Age, made the political unity of the USA irreversible and entrenched the ascension of the new superpowers of America, Russia, and the Central Powers bloc. It also gave ultimately irresistible momentum to the drive towards unification of the Americas and of continental Europe under the US and CP hegemonies respectively, a process started by the American Revolution and the Napoleonic Wars. Nonetheless, the outcome of the FGW had left that process critically unfinished. The great powers of Western Europe, the British Empire and the “Gallic” Franco-Iberian bloc, had been humbled and somewhat diminished, but not any crippled or destroyed yet, by that conflict. They would not concede their final and lasting submission to the aborning new world order without a further serious fight. In retrospective, looking at how much the strength of America and the Central Powers had grown during the 19th century, one might conclude that such stubborn resistance by the Western European powers was foolish and ultimately doomed to failure.
There was certainly a critical element of miscalculation and denial in the decision of London and Paris to gamble everything on the battlefield again: the advent of the Bourbon regime in France-Iberia could be credited as much as to the shock of defeat in the FGW and subsequent political turmoil as to revanchist denial of the changes in the international pecking order, a kind of collective “raging against decline” if you wish. It seemed that the Western European peoples reacted to the reality of their defeat by embracing the “stab in the back” legend. For the French it was the assumption that their country had been defeated by the disloyalty of “anti-national” domestic elements, and the weakening and demoralizing influence of liberalism, instead of the superior strength of the enemy. For the British, the blame was cast on the Great Rebellion, and they assumed that if India had remained quiet and loyal during the FGW, the British Empire would have triumphed. Regardless of the serious misjudgment of the revanchist powers’ public opinions about their previous military performance, it is probable that their ruling elites would have kept enough common sense not to chance a rematch so easily if the victor powers’ front had remained united. The split between Russia and the American-Central European front substantially changed the global balance of power, giving the League powers the reasonable expectation that if they played their diplomatic cards right, they could face their American and CP enemies with a neutral and benevolent Russia, or even joined to their side. This made the perspective of a general war look not such an uphill fight in London and Paris, even if they still underestimated the power of their adversaries.
Besides the lingering animosities that hailed from the FGW, and the long-standing rivalry between the USA and the British Empire on one side, France and the Central Powers on the other side, that went back to the Revolutionary Era, the Second Great War was the ultimate expression of the imperialistic competition for economic and political dominance of the world, that gripped all the great powers during the 19th century as an effect of global industrialization. Political factors just aligned this free-for-all rivalry into a structured clash between the blocs of Western Europe and America-Central Europe, with Russia playing a wild card. As a matter of fact, if one takes all the various factors that were driving the rival alliance blocs to a fight, they may wonder why the interwar period lasted so long, 36 years. There are various reasons that may account for it. First of all, the social shock of the FGW, the first total war of the Industrial Age, induced a lingering war weariness in European and American society that took a generation to dwindle completely and influenced the great powers to steer away from ultimate escalation to a general war while it lasted. Second, and no less important, colonial expansion of the European powers, and American focus on settlement of the Western Hemisphere, acted as a powerful “safety valve” for imperial competition: as long as the great powers could grab new markets and resources, and satisfy their ambitions for glory, in a much safer and easier way by conquering the pre-colonial states and colonizing the undeveloped areas of Asia and Africa, the impulse to fall on each other and rob their rival was substantially diminished and kept in check for decades.
The colonial outlet however could not work to defuse imperialistic hostility forever. By the end of the 19th century, the world, with the exception of China proper, had been partitioned into the empires of the great powers. The pressure to expand their own power and influence remained as high as ever, due to the socio-economic effect of industrialization and an international order that had carved the world into a few protectionist big blocs. American annexation of Brazil, the Scramble for Africa, Russian expansion in the Middle East and Central Asia, European colonization of South Asia and Southeast Asia, Japan’s and Egypt’s modernization, regional expansion, and integration in the alliance blocs, had all been important stages of this process that had left the great power wanting of further room to expand, short of falling on each other, or the complete colonial partition or joint colonization of China (an impressive task that at the very least required more long-term cooperation than the great powers were able to muster reliably).
A significant hallmark of the growing imperialistic rivalry between the great powers were the recurring international crises that intermittently marked the last quarter of the 19th century. Variously involving flashpoints in the typical areas where the spheres of influence of the great powers met and clashed, such as South America, Africa, the Pacific, Western Europe, the Middle East, the Balkans, Central Asia, East Asia, and Southeast Asia, they were too many, and their apparent causes often apparently too trivial, to be chronicled in a global history context. But their recurrence, increasing frequency, and ever more difficult peaceful solution, that often just froze them into unsatisfactory or instable compromises, were a manifestation of the underlying international tensions that gradually heightened during the 1880s and the 1890s. The arms race in the naval and land fields between the great powers, that spanned and steadily intensified during the last third of the 19th century, was another major manifestation of their imperialistic rivalry.
One event that in the opinion of many historians was a critical step in the path to the second world war was the so-called “Triple Entente” pact between Britain, France-Iberia, and Russia. Its genesis lies in the aftermath of the Eight-Nation War: Russia had been left unsatisfied and alienated by the other great powers’ veto to its sole protectorate over Manchuria, and the alliance of Japan with America and the CP, and turned to the Western European powers seeking an understanding that might guarantee its desired sphere of influence. On their part, London and Paris were eager, as long as Russian demands were reasonable, to bind the wild-card diplomacy of the Russian Empire to a stance that would guarantee its benevolent neutrality, or optimally its active support, in a clash with their American and Central European enemies. Contrasting Russian and British interests in the Middle East and China were a significant, but not insurmountable, obstacle, and in 1894, diplomatic talks ensued in the so-called “Entente Cordiale” between Russia and the League powers of Britain and France-Iberia. It involved a public non-aggression pact between the three powers, that bound them to neutrality in the case that Russia or the Anglo-French-Iberian alliance found themselves at war with one or more third powers; there also was a secret agreement that recognized Turkey and Manchuria within the Russian sphere of influence as far as Britain and F-I were concerned. The talks failed to establish a full-fledged military alliance between Russia and the Western European powers because of lingering Russian reluctance to bind itself so thoroughly and owing to the onerous demands of St. Petersburg for such an alliance (recognition of a Russian sphere of influence over Egypt and North China), which Britain balked to for the moment. Nonetheless, the three powers expressed their mutual willingness to re-consider further definition and recognition of a Russian sphere of interest in the Middle East and China, in the case of a general conflict.
Although it officially amounted to nothing more than a non-aggression pact, the Triple Entente was widely interpreted by the Western public opinion as a substantial change in the great powers’ alliance game, which bound wild-card Russia to benevolent neutrality towards, and -it was often suspected- an occult quasi-alliance with, Britain and France-Iberia. As a result, the Western European powers felt emboldened and took a more confrontational diplomatic and strategic stance towards America and the Central Powers. Conversely, the USA and the CP were driven to strengthen their own alliance ties and to assume an openly anti-Russian stance; international tensions and the arms race intensified in the following three years, till in early 1898, a “perfect storm” of various simultaneous minor international crises between the Anglo-French-Iberians and the USA or the CP occurred.
It was the combination of several minor flashpoints coming in rapid succession. The final straw were street incidents between French irredentist groups and German and Italian authorities in Lorraine and Savoy and clashes between UK colonial police and US settlers in the border areas of Patagonia. However, as much as popular imagination may like to single out the "Patagonia incidents" and/or the "Lorraine-Savoy troubles" as the main cause of the war, the international atmosphere had already been made tense in the previous months by the reopening of frozen border conflicts over some contested areas in Cameroon and Tanganyika, as well as disputes over the ownership of some islands placed between US Philippines and UK Indonesia. Taken individually, each of those flashpoints might have been far too trivial to justify a world war, especially in a different international atmosphere. But in the tense conditions of the late 1890s, their sum proved to be beyond the will or ability of the great powers to solve or contain by peaceful means yet again, and the heating antagonisms of the last thirty years finally reached the boiling point. The combined crisis worsened to a war fever and diplomatic escalation, then to mobilization of the great powers, and eventually in mid-1898 to a quick volley of declarations of war that squared the Alliance of the USA, Germany, Italy, H-C-S, Greece, Egypt, and Japan against the League of Britain, France-Iberia, and Turkey. Greece and Egypt joined the conflict out of their long-standing alliance commitments to the CP. Turkey did so out of its previous ties to the League powers and because of its irredentist ambitions on Greece. After the signature of the Entente pact, Russia had cranked up its pressure on Turkey to expand its own influence in the country and make it a client, with London and Paris making their unwillingness to intervene in the matter known to the hapless Turks. The Turkish government had reluctantly given in to Russian pressure, but given the strong popular hostility in Turkey to close ties with Russia, they had tried to compensate by stepping up their irredentist stance against equally unpopular Greece. Japan too joined the Alliance to honor its alliance treaties with the USA and the CP. Russia and Scandinavia instead declared their own neutrality for the moment, although they took a pro-League and pro-Alliance diplomatic stance, respectively. China was far too embroiled in its own domestic problems to play an active role in the conflict, although many Chinese hoped it might be a good opportunity to throw off colonial encroachment in their own land. The Second Great War had begun, and it would change the world.