According to the article, the Russians switched to using pens a year later as well, which implies pencils weren't such a perfect solution even for them.
I can imagine Russians let the Americans invent the pen and then just stole it. Total costs much much smaller anyway :)
Except that it was a private company that invented the pen and then sold it to the Russians and the Americans and even to the public. I am sure they have made back their $1million investment a couple times over.