People always talk about the web of alliances that helped cause WWI and how many of these treaties were 'secret'. Did world leaders really have no clue that two countries might be allied?
This is going to be a bit of a mess and I'm going to be jumping around a lot because there's just so much to talk about and each of these topics really deserve their own post. So pardon me if and when I brush over something.
So let's start from the top. First I'd like to point you to this map of Europe shortly before the war. These would be roughly the borders we're talking about from the beginning of our story (1879) to the end in 1914. Now, let's tackle this bit by bit:
The Congress of Berlin in 1878 is the preface to this whole discussion, mainly, as the instigator we can say for why Germany and Austria-Hungary initiated the first alliance of this supposed "mess". The Ottomans got their butts kicked by the Russians in the Russo-Turkish War and through a collective meeting of what were considered the "Great Powers" of the time, the Ottomans would have a significant portion of their European territory partitioned. The Balkans (Montenegro, Albania, Serbia, Bulgaria, Greece, and Romania in the above picture) would be carved up and released as independent entities...entities which would be greatly under the influence of the Russia who was the catalyst of their freedom and shared ethnic heritage.
Austria-Hungary now had an issue; Russia now had a bunch of influence in the Balkans, and formerly cordial relations between the two powers began to break down. The Balkans were and still are to this day chock full of nationalist sentiment and the Austro-Hungarians are a multi-ethnic and multi-national empire. This was seen as an immediate threat and Austria-Hungary looked North to Germany for support. Germany would accept and the Dual Alliance would be formed. This is where we briefly mention Bismarkian politics or what is more aptly referenced as the "3/5th's rule". That is, Germany must always have alliance 3 out of the 5 "great powers" as to secure the risk from total encirclement. In 1879 they would create a defense treaty with Austria-Hungary w.r.t. the mutual threat of the Russian Empire. This treaty would be made public a few years later.
Bismark would also try to secure Russia though at the same time. The Reinsurance Treaty was one of those secret treaties you talk about. It stated, simply, that as long as Germany didn't attack France and Russia did not attack Austria-Hungary that neither would get involved in each others wars. It was basically a non-aggression pact, one that heavily favored Germany as Bismark was trying to appease France not fight a war and it still allowed Germany to uphold her treaty with A-H and stay close. This was precisely what Bismark wanted -- he had completely secured his Southern and Easterly borders. With the addition of Italy to the group Germany would only have to worry about her French enemies to the West and a potential British threat in the North Sea.
When Willhelm II ascended his fathers throne in 1888 he had big shoes to fill and felt the need to do it on his own with his own new troupe of advisers, thus sacking Bismark to retirement and taking up the reigns of diplomacy himself. When in 1890 Russia (rather persistently) tried to renew the treaty for a more permanent, more alliance sounding one Willhelm II would just as persistently refuse. The Russian Tsar, Alexander II, would (rightfully so) feel exposed and without any friends. The British hated Russia and vice versa because of the Crimean War, Austria-Hungary was a natural enemy to them because of conflict in the Balkans, Germany was supporting Austria-Hungary and was giving him the cold shoulder, but France remained. Russia, exposed and in the open with rising tensions in the Balkans and having been economically supported by France for quite some time, formalized their defensive treaty against Germany. If one goes to war with Germany, they both do.
So, quick review:
This is the formal state of affairs going into the 20th century: Germany and Austria-Hungary have a defensive pact with regards to Russia. France and Russia have a mutual defense treaty against Germany. The United Kingdom is allied to no continental powers formally but is unfriendly to the Russian Empire (she felt Russia was encroaching on India/Persia/Afghanistan), neutral with the French Republic, and neutral with a leaning of cordial with the Germans. While the Dual-Alliance and the Franco-Russian Alliances were secret for a short time they are in the open now. Everyone knows of them. The only thing that was secret was the Reinsurance Treaty which lasted 3 short years.
Now, let's dive into the 20th century. In 1904 the French and the British would begin to create some of the first legitimate and lasting bonds of friendship in their entire history, a series of agreements called The Entente Cordiale*. It actually wasn't initially made with any regard toward Germany but rather a mutual understanding between the two powers. France would recognize the U.K.'s control over Egypt and likewise the U.K. would recognize French hegemony of basically the rest of North Africa Westward from there, Algiers and Morocco namely. The French and Spanish would divvy up Morocco between them (with the French getting the majority, obviously) and Germany would respond in its first major act of aggression -- the May 1905 Moroccan Crisis. Kaiser Willhelm II would sail to Morocco just as these deals were being finalized and gave a keynote speech with the Sultan in front of a large crowd crying out for Moroccan independence from "foreign oppressors" and that Morocco should remain independent and free from influence. This was an attempt to undermine French legitimacy and drive a wedge between the British and French relationships by giving the Entente Cordiale its first legitimate test. It would have the exact opposite effect as you might already imagine. The French and British, already uneasy by the German naval build up, would be pressed closer than they would at any point in history. While it would be nothing formal, Britain began seriously considering Germany a threat at this point and would, more as an act of informal policy and general thinking than anything else, lean toward supporting France in a theoretical European conflict.
In the mid 00's we would get a major technological event that would, in many ways, predicate the Russians and British reconciling their differences. That is, the coming of the Dreadnought. The Dreadnought was a new class of heavily armored, heavily gunned, short range battleships. They would completely and utterly outclass everything else out there by range and speed and firepower and accuracy and it many ways it would 'reset' the Naval Arms Race between Britain and Germany -- one which Britain formerly had the distinct advantage. While Germany was ostensibly building these for 'colonial protections', again, these were short range and heavily armed battle ships which had one purpose which everyone knew; to contest British naval control in their own backyard, the North Sea region and moreover block off Britain's entry through that gap that is Kattegat Bay, giving Germany free reign over the Baltic Sea as well. This fucking terrified Britain more than you could imagine as Germany was, at this point, the #2 industrial power in the world behind the United States. Refer back to the map on the top to get a more generalized view and you'll see what I mean.
