So I have been wondering how the trade system, particularly the trade routes work. I have made an example of Switzerland (landlocked country) to demonstrate.
As you can see in the picture below, Switzerland can trade with France, Germany, Italy etc. But NOT with the US, UK, Australia, China and so on. This is because "no possible trade route can be found". In the right picture you can also see that these trade routes are "opened up" if I annex Italy.
Now my question is this, why is there no trade route to China, the UK or the US..., but there is one to Sweden, the Soviet Union and the British Raj? My first guess obviously is that it is because the country is landlocked
, but why then can't Switzerland trade with China (which also lies on the Eurasian plate), if this is the case? 
As you can see in the picture below, Switzerland can trade with France, Germany, Italy etc. But NOT with the US, UK, Australia, China and so on. This is because "no possible trade route can be found". In the right picture you can also see that these trade routes are "opened up" if I annex Italy.
Now my question is this, why is there no trade route to China, the UK or the US..., but there is one to Sweden, the Soviet Union and the British Raj? My first guess obviously is that it is because the country is landlocked