It's way more likely that something like that would happen at the time Venezuela closed their borders and prohibited foreigners from leaving than now that they simply didn't pay some debit. It didn't then (got solved by diplomacy), it won't now.

Besides, Venezuela's military is large enough to be a threat to Brazil and Colombia. All on wars haven't happened on South America for a long time, it is very unlikely that one will simply happen between not-too-asymmetrical powers.

At least here in Brazil, the government would fall if it decided to send people to die there.