Catching up a little bit:
An interesting argument. I will hold to my statement that the borders were leaky, though. Some traffic was flowing across those borders even as they supposedly contracted.
I agree with you, and I never said it was an either/or situation. The Yileans benefited from full membership in the
Ziru Sirka, and they benefited again by using what they learned to forge a sizable rump empire out of the crumbling remains.
Keep in mind, however, that stories of 'leaking' technology are told from the perspective of the
Ziru Sirka, and the Vilani have an exceptionally rigid concept of intellectual property rights. If they invented a technology, they are the only legitimate owners of it; anyone else is either a licensee or a thief. The Yileans and Bwaps were almost certainly regarded as licensees, while the Vargr, Terrans and more radical Vilani breakaways (Sindalians, for example) were thieves.
There is one problem with invoking the Luriani - they are not CT canon, and nor are they unique canon in that there are at least three different versions of them...
Well, they are canon, regardless of which edition they showed up in. Traveller canon, according to The Powers That Be, works backwards from the most recent edition, so the -4100 contact between the Luriani and the Zhodani stands, as that has never been superceded.
I bring this up not to pick squabble over canon, but to allow me to note the interesting fact (at least to me) that the Zhodani are officially recorded as making initial contact with the Vilani in -2000, over 2000 years
after they first learned of their existence. Perhaps even more interesting is the fact that -2000 is just after declaration of the founding of the Rule of Man in -2004, meaning that the Zhodani waited until after the
Ziru Sirka was no longer in the picture before letting the other major human races know of their existence.
Or I suppose it could be that -2000 is just the date that knowledge of the existence of the Zhodani first leaked out from formerly proprietary First Imperium Bureau (Makhidkarun) sources. Makhidkarun does often come off as the most insular and secretive of the three former bureaux.