Oxymoron

The above clip comes from m-w.com, the online version of Merriam-Webster Dictionary.  Put simply, an oxymoron is a contradiction in terms, which brings me to the venerable Russian proverb of "доверяй, но проверяй," or "trust, but verify."

Per Wikipedia:

Trust, but verify was a signature phrase adopted and made famous by U.S. president Ronald Reagan. Reagan frequently used it when discussing U.S. relations with the Soviet Union ... Soviet revolutionary Vladimir Lenin also frequently used the phrase ... 

After Reagan used the phrase at the signing of the INF Treaty, his counterpart Mikhail Gorbachev responded: 'You repeat that at every meeting.' To which President Reagan answered, "I like it."

Here is the contradiction: If you trust, then there is no need to verify. Hence, the verification after the stated "trust" is, in fact, a statement that there is no trust after all.  This makes "доверяй, но проверяй" an oxymoron.  It is a polite way of saying:  "I don't really trust you, and this is why I will verify."

Knowing President Reagan's anti-communist stance, I understand his usage of the phrase when negotiating with the Soviets.  This is precisely why he responded with "I like it."

But, it makes me wonder why this phrase is a venerable Russian proverb.