I use to have this issue myself - there is really no way of knowing when it could happen, so it is always prudent (for more reasons than just this) to always have a backup funding method when traveling.
The biggest way to mitigate this issue is to set up to receive security and fraud alerts on your mobile phone. If there is a questionable transaction, USAA will send you a text which you can respond to. This will prevent the card from being disable if it is a false alarm. You can set this up through the Security Center in your on-line account.
I am so sorry for the frustration this situation has caused you. We would like for you to send us am email here at firstname.lastname@example.org with your member number, the details you provided above and the best way to contact you, so that we can get a bank specialist in touch to make sure this does not happen again. Thank you.
You need to look at this from a different point of view. It is impossible for any fraud detection system to be 100% accurate. There is always going to be some fraud that makes it through, just like there are going to be some valid charges that are falsely detected as fraudulent and blocked. It is very annoying when it happens, but it really is for the financial protection of both you and the bank. The best way to avoid a situation like this is to set up travel notifications before you leave home. You can either call USAA or set up the notifications yourself on the website. It only takes a minute and can help prevent this from happening in the future.