Not everything was cancelled, though. Of three major events that were expected, as late as August, to take place1
BCM August 1961, page 225
one did survive.
When I noticed that this event had, in fact, taken place my first assumption was that maybe it didn't include any East German competitors, since I'd seen the crosstable from a previous tournament, the one held in 1957, and it hadn't been enormous. But this was not the case: if we look at the results
Kažić, BM, International Championship Chess: a complete record of FIDE events. Batsford, 1974, pages 275-6
we can see that there was, in fact, a competitor from the GDR.
It's possible to explain this using dates: the tournament began on August 12, 1961 and the construction of the Berlin Wall began the following day. If we were to take it that the NATO policy on GDR visa, which predated the Wall, was neglected where chess was concerned, but then implemented rigorously when the Wall went up, that would be explanation enough - young Herr Kuettner would have already received his visa.
Well, maybe that's what happened. But where the policy pre-Wall is concerned, there's the curious question of the Berg en Dal, or Ubbergen, tournament, or Zonal. Or not.
From Mark Weeks' page on the 1960-3 cycle:
Uhlmann was refused a visa, the other Eastern Bloc nations withdrew in protest and the Zonal was subsequently, as it were, derecognised (and a new tournament organised). Mark goes on to give a clipping from Bob Wade's World Chess Championship 1963*:
This is one of those tit-for-tats in which N.A.T.O. countries have retaliated for the setting-up of the Berlin wall.But Wade was wrong. It wasn't. It couldn't have been, because the tournament took place in 1960
Di Felice, Gino, Chess Results 1955-1960, McFarland, 2010, page 396
which is how CHESS was able to give the crosstable in December of that year, and why the report above ("Uhlmann's unfortunate expulsion") is from the BCM for January 1961 (page 24).
That's seven months before the Wall went up, seven months before the World Junior Championship took place in The Hague and seven months before the BCM was able to report that three major international tournaments, all of which would have required the issue of visas to East German competitors in order to take place, were scheduled for the Netherlands.
I don't know why Uhlmann's appearance in the Zonal was particularly singled out in 1960.2 I guess I'd like to know, as I'd like to know whether Uwe Kuettner had any problems obtaining a visa, whether there were any other examples of the policy being implemented prior to August 13, 1961, and for that matter, when the policy was dropped, openly or quietly, afterwards.
I've nothing further planned on the subject, as it stands. There's presumably a long and comprehensive piece to be written - but not by me - on the effect of the Berlin Wall, the NATO boycott of the GDR and the visa crisis on international chess. But any further information, or just discussion, gratefully received.
[*Originally Arco Publishing, 1964 - see if you recognise some of the reviewers here]
[1 EDIT 15 July - as Mark Weeks points out, the proposed Interzonal date must have been January 1962, not 1961 as the BCM had it]
[2 EDIT 15 July - as Mark suggests, this may have been connected to restrictions on West German travel to East Berlin implemented in September 1960]
[Thanks to Richard James and Ian Kingston for images]