Look at the questions.

1.Is HCl an acid?

2.Which country does Liancourt Islands belong to,Japan or Korea?

For the first question,if I say it isn't and you say it is,you may prove your opinion by experiments,like dropping iron,calcium oxide,sodium hydroxide or calcium carbonate into it,so everyone believes HCl is an acid.

But for the second question,how can you have an "experiment" to prove your opinion? If you ask a Japanese and a Korean for answer, they may give you answers absolutely different., as both may be influenced by what their countries' governments say and believe the island belongs to the country in which they live.

Politics can make what was clear unclear.

Science can mak what was unclear clear.