But i still don't understand why Germany is being picked out !
Effectively Germany picked herself out. Its a long story of failed diplomacy, lost oppertunities, and pointless threats.
Bismarck had allied Germany to a large portion of eastern Europe to ensure that in any future war with France, the latter would be isolated and Germany safe from any other threats. This involved the Re-Insurance Treaty with Russia. This treaty was allowed to lapse when Russia was keen to renew it, primarily because Germany did not wish to keep balancing Russian interests in the Balkans with Austrian ambitions there. In the end, Germany preferred Austria as an ally over Russia. This left Russia as isolated as France had been from 1871 - 1890, and Russia was not keen to be in such a position, whilst France was keen to find any ally she could.
The German 2nd Naval Law put in place the German desire for a large fleet, but also named Britain as its likely enemy, and Tirpitz told anyone who listened that his fleet was being built to challenge Britain - the Riskflotte theory, where Britain would not be able to fight Germany without destroying her own naval power in the effort. Rather obviously this was not well received in Britain.
During the 2nd Boer War, the loudest condemnation of British action came from Germany, who also aroused much ill-feeling by supplying rifles and artillery to the Boers and when the war was ending the Kaiser boasted that he had supplied the British with the ideas of how to beat the Boers! This was not true, and the Kaiser had not made the claims to be malicious, but it did not go down well. After this Britain decided she would end her 'splendid isolation' and seek some form of agreement with a continental power. The first she approached was Germany, but the two could not find any agreement possible, something made worse by the German attempt to extort colonial concessions whilst refusing any agreement. The feeling was that Britain would have no option other than to agree any terms Germany would eventually offer, as the idea Britain would seek an agreement with France was seen as unthinkable by all the senior German figures except Holstein.
The Morocco Crisis saw Germany try to split the Entente as soon as possible, but she also continued to press matters with threats until Delcasse was removed from office, and Britain and France drew closer together in the face of German threats.
In 1908 when Austria annexed Bosnia-Herzegovina, Germany forced Russia to back down by threatening to allow the matter to go to war on Austria's decision, and that Germany would fight with Austria. Bulow, the author of this policy, told Bethmann when he took over as Chancellor that this should not be tried again, as Russia would not back down again - she had done so in 1909 because France and Britain would not support her.
The Agadir Crisis saw another crisis where Germany threatened war in order to gain colonial concessions from France. Germany had some justification in her view of French intentions, but decided to allow France to complete her action before even suggesting she may object, and then overplayed the objection. The German position fell apart when she ignored Britain for three weeks and Lloyd-George issued a warning that Britain would consider war preferrable to being 'counted as of no account' in international matters.
The Balkan Crisis on 1912/13 saw Europe close to war, but this time Germany worked with Britain to avoid war and it worked well, which sadly worked against peace in 1914 when Grey based his policy on Germany following a similar line, whilst Germany decided to try and enable Austria to fight a limited war - despite Austria considering it impossible to do this from the outset!
This is just a skim over the reasons other nations were against Germany, not all, but some of the main ones, and there is certain justification for the actions of Germany too. The main problem was that German policy was flawed over a long period which only pushed her likely enemies closer together and ensured all stood against her when war did arrive.
I hope this summary helps somewhat, even if it only guides you to look at these incidents in more detail.