I am not even sure if this is possible, but I had a thought one time when I was browsing some Wikipedia articles. Basically, it seems like a lot of landlocked countries exist because they were once buffer states or because that's just where different people lived. Most countries depend on a coastline in order to have their own access to shipping routes, otherwise they'll have to rely on their neighbors. This seems to be why there used to be very few landlocked nations used to exist. At the start of WW1 there was only Luxembourg, Switzerland, and Serbia. Nowadays there's those three along with Belarus, Macedonia, Kosovo, Czechia, Slovakia, Austria, Hungary, and Moldova (and San Marino and the Vatican but you know). So I thought about how (or if) it'd even be possible to have a world with no landlocked nations. Landlocked nations can still have previously existed, but by 2019 they must all be gone. Any thoughts as to how (and again, if) this would be possible?