“It was obvious to us that this was the only tough security structure there was in the world, and that the membership of NATO would only mean benefits for Poland,” Mr. Kaczynski said in an interview last year. NYTBut threats need to be credible to work--one has to believe that the allies will come to the defense of the attacked, and, of course, many wars occur precisely because folks do not believe that this will happen (see Glenn Snyder's Alliance Politics). Expanding NATO to include countries that have little, if any, ties to NATO members and ones where NATO could do little in terms of conventional military activities to help would raise questions not just about the commitment to those countries but to the rest of NATO. Commitments can be seen as interdependent--that credibility and reputation in one spot just might be related to credibility and reputation elsewhere (although academics debate this).
And who in NATO should care most about the credibility of NATO's defensive commitments? Not Belgium. Not Germany after 1991. Poland. Particularly given its pre-WWII experience, Polish leaders should be most concerned about cementing alliance ties so their country does not get hung out to dry again. Instead, the late President saw Poland's security based on containing Russia via alliances with Georgia and Ukraine. This is not entirely unreasonable, but shows that there are multiple ways that countries can pursue their security, even if one is just focused on alliances (putting aside other means like arms buildups, economic development, supporting secessionists in one's adversary, etc).
Rather than pondering how the Katyn massacre continues to haunt Poland, I thought I would ponder how realism's indeterminacy continues to haunt me.