As part of the agreement, Ukraine`s signatories offered « security guarantees » in exchange for compliance with the Nuclear Non-Proliferation Treaty. The memorandum gathered a series of assurances that Ukraine had already given to the Final Act of the Conference on Security and Cooperation in Europe (CSCE), the UN Charter and the Nuclear Non-Proliferation Treaty, but the Ukrainian government found it useful to have these assurances in a document specific to Ukraine.   « Cooperation in the defence industry is important to the development of our strategic partnership and I am pleased that we are strengthening it today, » he said of an interpreter. When Russia conquered Crimea this year and continued to support the separatists, some Ukrainian government officials called for a return to nuclear weapons to prevent Moscow from cutting and dividing their nation. When he was Defence Minister in September, Valeriy Heletey spoke about the possibility: « If we cannot protect Ukraine today, if the world does not help us, we must return to the development of nuclear weapons that will protect us from Russia. » Other officials spoke in the same way at the beginning of the year. ISTANBUL – Turkey and Ukraine signed military cooperation agreements in Istanbul on Friday, deepening a defense partnership seen as an attempt to balance Russian rule in the Black Sea region. Last year, Ukraine agreed to buy Turkish drones. According to reports, the two countries are also in talks to develop an aircraft engine. On March 24, 2014, Canadian Prime Minister Stephen Harper led the G7 partners to an ad hoc meeting at the Nuclear Security Summit in The Hague for a partial suspension of Russia`s membership due to a violation of the Budapest Memorandum by Russia. He said Ukraine had abandoned its nuclear weapons « on the basis of an explicit Russian guarantee of its territorial integrity. » By no longer committing this guarantee, President Putin has provided those who need little more than those already created by pride or resentment to arm themselves to the teeth. Mr. Harper also expressed support for Ukraine by saying he would work with the new Ukrainian government on a free trade agreement.  Harper died in the General Election on October 15, 2015 and resigned as leader of the Conservative Party.