Why did nationalist developements such as pan slavism and the two balkan wars increase tensions to such a great degree?

Nationalism:

"A person or a any number of people belonging to a specific origin having an over exaggerated form of love and affection for there nation or country is categorized as a nationalist and the concept is termed as nationalism."

A nationalist person places his countries interests in such a manner that it makes him more conservative minded. For any nationalist his country's interests holds an edge over all the other states or nations.

Explanation:

Pan Slav-ism And the two Balkan wars:

So, we will say that it all started in the Czech republic in 18th century, as Slav is a nation and they were left deprived of there rights by the Austrian rule and things were not going well for them in the country.

For this reason the scholars, politician, along with all the youth formed a nationalist campaign, which was against the powerful Austrian rule or mainly the Austrian empire in that time.

Consequence:

As due to the Pan Slav-ism a congress of Slav nationalists or representatives was formed. The congress formed was in favor of giving more rights to the the Slav people. Along with that the Austrian Empire was weakened due to the campaign, run by the people against them.

The Two Balkan Wars:

First Balkan War:The Slav nationalist's had most of the conflicts and problems with the imperial rule which was weak in that time. The Ottoman empire was very weak and as they had limited power over the vast area of the empire. While there were counties and tribal system in the European region. They formed a group of nations serving the same purpose, which was then called as the Balkan League (Serbia, Bulgaria, Greece, and Montenegro) as they demanded freedom and were ready to fight for it. As for the members of the Balkan League, they wanted a region free of any imperial rule. As the Slav's had a campaign against the Ottoman empire, as well as the Austrian rule in the region. As all of this freedom fighting took the shape of a war, and was then refereed to as the first Balkan War.

2. Second Balkan War And the spoils of war: The Balkan League included a number of countries who fought together against the imperial rule and they fortunately won in the end. But, things did not ended up well for them as the Bulgarians were not satisfied with the fair distribution of the spoils of war among the league members. As they argued about the unfair distribution of the spoils of war, which resulted in a war against there former friends and allies, Greece and Serbia.

After, which the situation got much worsen and Bulgaria attacked Greece and Serbia, to which both of the countries responded in very heavy manner. Both, Greece and Serbia directed there armies to invade the country and they entered inside the Bulgarian region.