[Milsurplus] Selecting auction winner?

[Hue Miller]

I am thinking about putting up a couple items or so, on auction,
but i am having some concerns - i do NOT want these items to
leave the USA, silly me. I am concerned that one overseas bidder
may circumvent my wishes. Are there any countermeasures i can
take, practically, or should i just forget the "public auction" ?
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If you feel this topic is inappropriate to this list, this is my only
post on the subject, and respondents may choose to reply to me
off-list.
Tnx, Hue Miller