Bismarck urged not to hinder Russia from going deeper into the "oriental dead end." What did he mean by "oriental dead end?"

Question

In his letter of 03 May 1888, Otto von Bismarck, the then-Chancellor of Germany, wrote to Prince Heinrich VII Reuß, the then-Ambassador of Germany to Austria-Hungary:

Durch einen Angriff auf das heutige Rußland würden wir seinen Zusammenhang festigen; durch Abwarten seines Angriffs aber können wir seinen inneren Verfall und seine Zersetzung möglicherweise früher erleben als seinen Angriff, und zwar um so früher, je weniger wir es durch Bedrohungen hindern, tiefer in die orientalische Sackgasse hineinzugehen.

Here's my translation:

By attacking Russia now, we would only strengthen its cohesion; but by waiting for Russia's attack on us, we may witness Russia's decline and dissolution sooner than its attack - the sooner the less we hinder Russia by threats from going deeper into the oriental dead end.

This statement caught my attention, especially the reference to the "oriental dead end." Why oriental, and why dead end? A hypothesis of mine is that Bismarck meant to compare Russia with the then-declining Ottoman Empire, implying that both were going down the same dead-end road. However, I find it difficult to see how Russia and the Ottoman Empire were on similar paths.

Why did Bismark think that Russia might dissolve on its own, after all? That's especially puzzling in view of the fact that Bismarck said in the very same letter that if Russia lost a war and got disintegrated by a treaty, Russian states would quickly reunite "like mercury drops."

I humbly hope that history experts on this SE can solve the mystery as to what exactly Bismarck meant by "oriental dead end," and help me make sense of his words.

Answer 1

The quoted letter includes a written dispute between Bismarck and Crown Prince Wilhelm. Wilhelm annotated the sentence about Russia walking into the "dead end":

Es hat aber leider die Sackgasse gemerkt, und zeigt bisher verzweifelt wenig Lust hineinzugehn.

Unfortuantely, it noticed the dead end, and for now shows desparately little will to enter.

Bismarck then added another margin:

doch, es geht hinein, sobald Österreich aufhört es zu hindern.

yes, it will enter, as soon as Austria stops to prevent it.

The following text in the source, No. 1341, is a letter from Bismarck to Crown Prince Wilhelm, where he discusses their differences in detail. It contains the following sentences:

Die geheimen Verträge, welche wir mit Rußland haben, sind Ew. Kaiserlichen Hoheit bekannt. Ihr Text gibt die Gewißheit, daß Rußland beabsichtigt, in die „Sackgasse" hineinzugehen, und es würde schon darin sein, wenn es nicht auf unser Verlangen durch österreichische Opposition daran gehindert würde.

The secret treaties which we have with Russia are known to Your Imperial Highness. Their text makes it certain that Russia intends to enter the ‘dead end’ and would already be there if it were not prevented from doing so by Austrian opposition at our request.

To me, this sounds like a reference to the secret Reinsurance Treaty of 1887. In that case, the "dead end" could be a Russian attempt to intervene against the Ottoman control of the Bosphorus and the Dardanelles with military force:

Ganz geheimes Zusatzprotokoll

2. In dem Falle, daß Seine Majestät der Kaiser von Rußland sich in die Notwendigkeit versetzt sehen sollte, zur Wahrung der Rechte Rußlands selbst die Aufgabe der Verteidigung des Zuganges zum Schwarzen Meer zu übernehmen, verpflichtet sich Deutschland, seine wohlwollende Neutralität zu gewähren und die Maßnahmen, die Seine Majestät für notwendig halten sollte, um den Schlüssel seines Reiches in der Hand zu behalten, moralisch und diplomatisch zu unterstützen.

Translation from Wikisource:

Additional Protocol

2. In case His Majesty the Emperor of Russia should find himself under the necessity of assuming the task of defending the entrance of the Black Sea in order to safeguard the interests of Russia, Germany engages to accord her benevolent neutrality and her moral and diplomatic support to the measures which His Majesty may deem it necessary to take to guard the key of His Empire.

While it is clear that just like the Crimean war, a Russian attack on the Ottoman would trigger a reaction by England and France, I do not understand why this would have the potential to destroy the Russian Empire, as claimed in the Bismarck letter to Reuß.

Another text in the collection, No. 1343, a memorandum for then-Emperor Wilhelm II before his state visit to Russia, explains Bismarck's thoughts some more:

Wir können...dem Kaiser von Rußland nicht auf Kosten Österreichs Dinge im Orient versprechen, die uns die Freundschaft Österreichs kosten würden. Wir müssen uns die letztere erhalten. Wohl aber können wir die russische Politik gewähren lassen in Richtungen, welche für Österreich keine Lebensfrage bilden; also in der asiatischen Richtung einschließlich des Schwarzen Meeres, der Meerengen und selbst Konstantinopels...Rußland würde durch Erwerbung Konstantinopels nicht stärker, sondern in sich und durch die Feindschaft Englands, unter Umständen auch Frankreichs, welche der Besitz Konstantinopels mit sich bringen würde, eher schwächer, jedenfalls weniger gefährlich für uns werden. Wir haben deshalb keinen Grund, Rußlands Streben nach den Meerengen zu hindern. Das ist dem Kaiser Alexander amtlich bekannt.

We cannot...promise the Emperor of Russia things in the Orient at Austria's expense that would cost us Austria's friendship. We must preserve the latter. We can, however, allow Russian policy in directions which are not a matter of life and death for Austria, i.e. in the Asian direction, including the Black Sea, the straits and even Constantinople... Russia would not become stronger through the acquisition of Constantinople, but rather weaker in itself and through the hostility of England, and possibly also of France, which the possession of Constantinople would entail, and in any case less dangerous for us. We therefore have no reason to hinder Russia's endeavours to gain the straits. The Emperor Alexander is officially aware of this.