The thing I want to know is... why?? What could you possibly learn from these spies that you couldn't learn just by having a few American newspapers delivered? Why go through all the bother of planting these people all over the place considering the risk of discovery? Am I missing something very important here?
In times of peace, prepare for war. It's much, much more difficult to plant a spy during an actual war. If you're going to plant some, do it in advance. If the nations cut diplomatic ties, those spies will still be able to report everything. If anything, it's much cheaper to do some spy mission when ties are cordial, rather than when everyone's panicking and security is all tied up.
Yeah, there are spies everywhere now. My country has some in yours and yours has some in mine. Even if you live in some small country like Slovakia or Brunei. It's no surprise they were caught, and certainly no surprise that they were attractive and nice people. If your country does something as low as planting undercover cops to bust crime rings, they're certainly capable of espionage.
Most of the time they don't actually do anything. There's always plenty of information to steal though. The latest weapon plans. Military locations and plans. Encryption systems. Soviets stole the plans for nuclear weapon technology when both were allies. They planted their spies well in advance, and it's likely that they're doing the same thing again.