Balance of Power In Middle Earth

Broad International Context in Middle Earth.

Now, that the basic background of the Real World ideas we can start to examine the political context of Middle Earth itself. One important thing to look at here is the major timeline here. The War of the Ring started in Year 3018 of the Third Age. Before that, the only major conflict was the Battle of Five Armies. That took place in 2941 of the Third Age - 77 years prior to the War of the Ring. The most recent full scale war that I know of was the war of Dwarves and Orcs, which ended in 2799 of the Third Age. This means a solid 77 years of total peace and 219 years without a major conflict. This period ends with the resurgence of Mordor and its attempt at hegemony. This would naturally realign the entire geopolitical and international order. But this 219 period of peace would define the political actions of the major players.
This has direct real world analogues to the period prior to World War One. In that period there was a major period of peace. The timescales are a bit different, but the overall outcomes are the same. This period as I define it started with the end of the Napoleonic Wars and ended with World War one. Within that was the wars of Italian and German Unification. These upset the balance of power in Europe, but did not seriously risk the rise of a major hegemonic power. Just as important was the fact they were short, limited wars with small human and economic costs. This is very similar to the Battle of Five Armies to me. It created a new nation state that became a major land power. It was also similar in that the battle was short with limited costs.
So, what was the major defining features of this time period? First, while there were major powers, none were able to dominate the other powers. Even with increased industrialization and and military spending, no one could come to dominate the international order. As a result, the major powers tended to act in terms of the balance of power. Any nation seen as too strong would produce alliances meant to counter the influence of the offending nation. Initially France was the power everyone was afraid of. Eventually, Europe appears to have been divided between those who felt Russia was the main threat (Germany, Austria and the Ottomans) and those who feared Germany (France, the UK and Russia to a degree).
Deterrence was the name of the game. Each power feared the rise of a superpower and revolution. The French Revolutionary Wars and the Napoleonic War unleashed the revolution allowed for showed the power to destabilize the entire continent. It unleashed a 23 year period of almost continual wars that proved some of the most destructive prior to the World Wars. As a result, this was a period of classic defensive realism. To prevent the rise of a second Napoleon, defensive alliances would be formed and reformed based on current conditions. To prevent returning to the revolutionary violence of the Revolution, nations would actually send troops to defeat revolts in other nations. A classic example of this latter tactic was the Russian intervention in Austria to put down a revolt aiming at Hungarian autonomy or secession.
Where the comparisons end though are in how this period of peace itself ends. In the build up to World War One, the collapse of the Ottoman Empire was a huge contributing factor. This created the quite new Balkans Nations like Greece, Romania and (most importantly) Serbia. These were nations that could reasonably be seen as buffer states in the Balance of Power System. They were created out of territories of the Ottoman Empire and served as barriers to Austrian or Russian expansion in the same region. Thus major powers were contained here.
But this proved to be a major vulnerability in the system. First, the Austrians were able to annex Bosnia. Serbia (along with some other powers) became a vehicle for Russia to expand its influence indirectly. The clear decline of the Ottomans also created perceived openings for Russia to finally take control over Constantinople. Access to warm water ports had been the cause of the Crimean War. Ever since then, the balance of power idea had deterred Russia from acting in the area. But with one of those powers not able to resist the smaller Balkan Nations in 1912, deterrence was losing its value. Italy acted on this perceived opening when it invaded the Ottoman Empire's Libyan provinces.
The second was the rise of new threats. As noted above, Russia and Germany were growing. Russia by 1914 was recovering its political, military and economic power after its defeat in the Russo-Japanese War and the revolution of 1905. Germany was newly unified and rapidly becoming a new economic and military power. Its larger population, manufacturing power and General Staff meant most other nations saw it as a major land power.
This produced two major problems for the Balance of Power system. First, Germany began to see Russia as a growing and existential threat - with the time to defeat it. Germany felt that war with Russia should come sooner rather than later, otherwise it might lose the seemingly inevitable war. The power of the German army produced fears in France, who had been on the losing end of the Franco Prussian War. This was the last major European great power war and occurred before the population and industrial growth of Germany. German increases in naval spending produced a naval arms race that produced British fears that the Germans were attempting to challenge them as well.
Then there was the alliance system. The system worked best when it was based around temporary ad hoc coalitions aimed at dealing with specific threats. But as World War One drew closer, alliances became more formal and entrenched. Leaders felt they had to back their allies in a crisis otherwise these alliances might not last. Germany and Austria were both particularly keen on preserving their alliance, as they did not feel they could survive without it. Add in a toxic interpretation of Social Darwinist militarism and obsession with prestige and leaders could not afford to "back down". This then pulled these alliances into wars they would not have otherwise wanted. Granted, there was always room to do so, like Italy did. It refused to fight along side its nominal allies. It even dealt the fatal blow killing the Austrian Empire in that same war. But this system meant that such shifts became increasingly unlikely.
Lastly, there was the rise of nationalism. Russia's involvement in the Balkans was inspired by its belief in Pan-slav ideology. It felt that it was its job to protect the slav populations in the area - meaning that it was willing to be more involved than most powers would have been. These Balkan nations felt that their entire reason for existence and legitimacy centered on the government's ability to protect their ethnic nationals under their control and liberate those outside their borders. This led to conflicts between them, plus fighting between them on one side and the Ottomans on the other. Serb radicals felt that it was their mission to liberate Serbs controlled by the Austrians.
This then produced a feeling of impending doom in the Austrian Empire. In the 50 years prior to World War One, states based representing the will of specific ethnic groups and controlling their homelands started growing. Germans and Italians were noticeable ethnic minorities. There was a fear that these populations might try and break away so they can join their nation states. Germany and Italy both had histories of waging war to solidify control over territories with their respective ethnic groups. Germany won one such war against Austria. Italy was open about its desire to control the Italian sections of the Austrian Empire. Hungarian nationalist revolts were successful in forcing the government to concede to a degree of federalism.
But most problematic was Serbia. It was the most radical in its nationalism and was backed by Austria's imperial rival - Russia. Like Italy, Serbs lived in Austrian territory and the nation state in question wanted to control those people. So, when Serb sponsored terrorists assassinate or attempt to assassinate Austrian officials with the aim of taking away its territory, Austria naturally felt it was in a battle for its survival.
Now, how well does this translate to Middle Earth? Well, we have the rise of the Lonely Mountain after the epitome of a limited war with decisive battle. This would naturally unsettle the international order in the same way Germany did and Moria would if the dwarves retook it. Growing ethnic strife is occurring between the Wild Men and Rohan, though it does not appear they are seeking a homeland. This ethnic struggle does play out with the attempts to retake Moria and the War of Dwarves and Orcs. All the other major states appear ethnically homogenous and well established. The alliances all appear to be stable. Also, Gondor appears to not be faltering under its own ethnic tensions. Instead the combination of poor leadership, poverty and disease took its toll. So it looks like many of the systemic level risks that led to World War One were not present at the start of the War of the Ring.
The rise of a nation attempting to become the sole superpower in Middle Earth was the root cause of the War of the Ring. Mordor and Isengard were the main, if only factor in unsettling the establishment. Now, we know that the Third Age was effectively like a medieval Cold War. The White Council knew Sauron was not dead, so knew to prepare for war. Actions both sides took were the sort of indirect actions aimed at undermining the enemy the same way Cold War era powers did. Gandalf raided Dol Goldur and organized the killing of Smaug - both out of a desire to contain Sauron. He in turn used his base in Dol Goldur to weaken his allies before Mordor was ready to declare full war. The hunt for Gollum was part of the covert intelligence battle both sides played. As were the secret deployment of the Ring Wraiths.
So when Mordor became a threat again, there was more of a similarity to the Rise of the Nazi regime. Now, this is not a direct connection, as there was some some debate as to whether Hitler could be trusted and if he was an actual threat. No such delusions would be present with Sauron this time around. But there were some skepticism about his return. Similarly, the tensions gradually rose. World War Two proceeded at first through escalation of tensions with the occupation of the Rhineland, German rearmaments (in secret at first), the Spanish Civil War and so forth. There was also several fronts that eventually melted together, like Italian invasions of Ethiopia and the Balkans or the Japanese invasion of China. Even after the invasion of Poland, there was a period of time that little happened. The battles did not jump straight from Poland to Stalingrad.
In Middle Earth, a similar thing happens. Skirmishes involving the Fellowship in Moria and Amon Hen took place at the sort of dividing line between the cold and hot wars. In the battles between Isengard and Rohan, it escalates from Wild Men and orc raids on villages to the Fords of Isen to Helm's Deep. The Rangers of Gondor were conducting ambushes against the enemy troops marching to Mordor long before the main attacks came.
From this, we can assume that the prelude to war was as if the Free People of Middle Earth operated on the Balance of Power principle amongst themselves like Europe did prior to World War One. Its relations with Mordor and its allies was more akin to the Cold War. The eventual transition from cold to hot war was more like the build up to World War Two.