Russian-Nukes copyUkraine may have to arm itself with nuclear weapons if the United States and other world powers refuse to enforce a security pact that obligates them to reverse the Moscow-backed takeover of Crimea, a member of the Ukraine parliament told USA TODAY. The United States, Great Britain and Russia agreed in a pact “to assure Ukraine’s territorial integrity” in return for Ukraine giving up a nuclear arsenal it inherited from the Soviet Union after declaring independence in 1991, said Pavlo Rizanenko, a member of the Ukrainian parliament. “We gave up nuclear weapons because of this agreement,” said Rizanenko, a member of the Udar Party headed by Vitali Klitschko, a candidate for president. “Now there’s a strong sentiment in Ukraine that we made a big mistake.” His statements come as Russia raised the possibility it may send its troops beyond the Crimean peninsula on the Black Sea into the eastern half of Ukraine. MORE