Not sure about lions and elephants. However, global warming and resulting climate shifts may eventually leave us with no other choice than to redistribute existing species according to our understanding, and will likely imply the need to breed/engineer new ones sooner or later anyway.
What will become of it is of course a totally different question.
In view of that perspective, politically speaking, the issue is whether or not it would be a positive factor if it were the US who became the "lab rat", yet again paving the way for future strategies or serving as a deterrent for other nations.