Born in 1955 in Khrystynivka, Cherkasy Region, Smeshko has made a career as a professional soldier-scholar. He holds a doctorate in Military Cybernetics and served as professor of information systems and systems analysis, publishing over 100 papers. In 1992, he became secretary of the Science Advisory Council of the Ukrainian Ministry of Defense. That same year he was reassigned as Defense Attache to the Ukrainian Embassy in Washington D.C. where he spent 4 years. While there he negotiated a memorandum of military cooperation with the United States during that time. In 1995, Smeshko was awarded a general's star and recalled to the Ukraine to lead the president's committee on intelligence, which he did for 3 years. In 1997, Smeshko was appointed Chief Directorate of Intelligence of the Ministry of Defence of Ukraine where he uncovered "massive fraud" in weapons end-user certificate production indicative of arms trafficking at the SBU, then headed by Leonid Derkach. Smeshko implemented stricter controls, particularly for the Kolchuga air defense system.
In 2000, facing political attacks organized by the SBU, Smeshko resigned from his post as head of the Military Intelligence Directorate and assumed the post of Defense Attache to Switzerland, a demotion. In this position, he negotiated a memorandum of military cooperation with Switzerland. In 2002, Smeshko completed a masters in Military Administration and a Law Degree from Shevchenko University in Kyiv. In late 2002, Leonid Kuchma asked Smeshko to return to Ukraine to assist him in handling accusations made by the U.S. State Department that Ukraine had sold the Kolchuga system to Iraq. Later that year, Derkach was fired and Smeshko was appointed head of the SBU. He immediately set into action with a plan to preserve documents, replace top management and reorganize the agency with new pay scales and a mission focused away from KGB style secret political police.
Smeshko was instrumental in the prevention of military action against the civil protests in late 2004. He demanded General Popkov stop his efforts to crack down on the protesters, as the General was mustering 10,000 troops to do so. The SBU and the military intelligence directorate worked to block the fraudulent ascension of Viktor Yanukovich, supporting Viktor Yushchenko.
In 2005, Yushchenko fired Smeshko from the SBU.
Smeshko speaks fluent English, German and French.
Smeshko has been implicated in the poisoning of Viktor Yushchenko. A parliamentary commission investigating in October 2004 confirmed that Smeshko dined with Yushchenko on the night of September 5, 2004, where he may have been poisoned. Yushchenko claims to have fallen ill about 3 hours after the dinner and sought medical treatment the following day. Smeshko credibly denies the allegations, citing the existence of several other theories regarding the poisoning, and claims that the allegations were made by Kuchma supporters from within the security services, including former SBU chief Derkach.
According to disgraced Undersecretary of Defense John A. Shaw, in support for what is now considered to be a fabrication, Smeshko was a participant to several high-level meetings held on February 10–12, 2004, between Smeshko, Shaw and Shaw's personal friend, MI6 Director Richard Dearlove. At these meetings Shaw claims that Smeshko provided intelligence confirming that Iraqi WMDs had been moved outside of Iraq by Russian Spetznaz forces. Shaw's Ukrainian-American aide was friends with David Nicholas, U.S. OSCE Ambassador to Ukraine, and Smeshko. Smeshko knew Richard Cheney and General James Clapper from his time as Defense Attache in Washington when they were, respectively, Secretary of Defense and Director of the Defense Intelligence Agency. These reports were determined to be false by an investigation led by Charles Duelfer.
Smeshko, however, has emphatically denied Mr. Shaw's account of the meeting, and claims that it was convened under the false pretense of imparting urgent information from Vice President Cheney to Ukraine's President. He further notes that, contrary to Mr. Shaw's account, Lt. Gen. James R. Clapper was in attendance, and M16 Director Richard Dearlove was simply represented by several British intelligence officers. All participants were surprised when Mr. Shaw changed the stated purpose of the meeting and, instead, requested that Ukrainian Intelligence provide the U.S. Government with any information it may have concerning WMD in Iraq. Smeshko's immediate and unequivocal response was simply: "We have absolutely no information concerning this matter." After a few (embarrassed) minutes this unexpected meeting came to an end.