Well, as a Discordian, I can tell you all statements are true in some sense, false in some sense, and meaningless in some sense.
In RISK, if someone is holding the entire continent, or is about to, It does beehoove you to get involved, and take at least one territory to deny them the Bonus.
So, Goldman was probably making sly reference to Vietnam. The book was published in 1973, not ‘before Vietnam’ but rather, during. Goldman was also involved with the screenplay, but I haven’t read the novel, so I don’t know if the ‘Land war in Asia’ line is original or added. Anyone Know?
It’s on my list. My Library’s copy never seems to be in. Hard to belive He’s the same author who gave us ‘Magic’, the original homicidal ventriloquist’s dummy.
Though there are important things to get in Risk, you have to stay flexible.
I’d agree that North America and Australia are the best prizes, followed by S America and Africa. Also it’s important to keep an eye on the number of cards held by a player who is about to get splatted… he might make a great target. Also, getting a card every turn is important in my strategy too.
I win most of the time, probably because I don’t drink when I play. O’course you have to play a lot of games to see if you are good at it, a small army can win against a huge army if the dice favor them. That’s always exciting.
I knew the Vietnam War either was happened at the time or had happened before The Princess Bride was published. My post was poking fun at the various things Goldman, in his guise of S. Morganstern, put in the story to narrow down a not-so-specific time frame, such as, “this was before blue jeans.”
I got that when I started reading it again last night. (I needed something to read, it was already out, “OK,” I said.) It’s still a fun read, I’m pleased to note.
O’course you have to play a lot of games to see if you are good at it, a small army can win against a huge army if the dice favor them. 
That’s always exciting.