Bumping up this old thread, first for a general rant, followed by a question.

Rant mode on: it seems like the hardest thing I do when I travel is to figure out European rail issues. Flights and hotels are easy, but rail is a nightmare. No coordination between systems, very odd regulations that seem to tangle me up, no ability in many cases to book online and print your own ticket, most sites (German Rail seems to be an exception) won't send tickets to the US, I could go on. Right now, I'm trying to figure out how to get from Brussels to Strasbourg. Well, Belgian rail shows me a schedule, but won't let me price the trip since apparently you can only price destinations that are one country away and Luxembourg is between Belgium and France (that's the best explanation I've seen). French rail won't issue the ticket since the origin isn't in France. Germany rail has a spectatular site (only the Germans will offer you "seven ways to buy your ticket") but that also only works for travel beginning in Germany. For another trip I can book and pick up my ticket at the train station in Paris, but they are very clear that the machine will want a french credit card. I know you can do some of this through rail europe, but they are very pricey. I'm very surprised that there isn't some central online booking agency other than Rail Europe, but I haven't found one.

Now the question. I'm going from Brussels to Strasbourg and then from Strasbourg to Paris and then from Paris to Brussels in late August/early September. I know this is high travel season. Do I really need to worry about booking in advance or would I be OK just showing up in Brussels - probably the night before - and buying the tickets then? (As a side question - is there a full ticket station at the airport, or do I need to go to the station in Brussels itself?) I figure I can buy the tix for Paris when I arrive in Strasbourg three days before the trip to Paris and again can buy the ticket for Paris to Brussels when I arrive in Paris. In any of these cases will I run into problems with fully booked trains or the inability to reserve a seat?