Why would the incidence of rape rise 60% in ten years?

For as long as records have been kept, the incidence of rape in the U.K. (Great Britain) had been lower than here in the U.S. Then starting in 1997 the rate began rising sharply in the U.K. It rose 60 percent in the next decade and is now twice the rate in the U.S.

What in the world could have caused this?

While it's impossible to know for sure, it's worth noting that in 1997 the U.K. banned citizens from owning a handgun.

We're guessing that the argument--as here--was that it would reduce crime and increase safety.

Sure doesn't seem to have made women safer.