Ukrainian President Volodymyr Zelensky has every right to feel deeply aggrieved over his shameful treatment at the recent Nato summit, where he failed to secure a firm commitment that his country will ultimately be allowed to join the alliance.
Zelensky had travelled to the Lithuanian capital Vilnius, the venue for this year's summit of Nato leaders, in the hope of securing a clear timetable for Ukraine to become a fully fledged member of the alliance.
From Kyiv's perspective, Ukraine is at the forefront of Nato's effort to prevent Russian President Vladimir Putin from threatening the security of Europe, and much of the military equipment Ukrainian forces are using to defend their territory from Russian aggression has been provided by Nato member states such as the US and UK.
Zelensky, moreover, believes there is a compelling case for Ukraine to be granted full membership of the alliance after Finland and Sweden, two countries that previously took pride in their neutral status, were granted membership status.
"Ukraine also deserves respect," Zelensky tweeted on the eve of the conference. "It's unprecedented and absurd when timeframe is not set neither for the invitation nor for Ukraine's membership."
Yet, despite being given a rock star welcome when he addressed a cheering crowd in Vilnius's Lukiskes Square – just a few kilometres from the summit – Zelensky's plea made little impression on the assembled Nato dignitaries. Rather than securing a firm commitment on the membership issue, all he received was a vague commitment that Nato leaders continued to support the notion of Ukrainian membership, with the addition of the caveat that "we will be in a position to extend an invitation to Ukraine to join the alliance when allies agree and conditions are met."
While the vagueness of the offer will have come as a big disappointment for Zelensky, it will have delighted the Kremlin, which remains totally opposed to Ukraine joining the alliance. Indeed, Ukraine's long-standing desire to forge closer ties with the West was one of the main arguments Putin made to justify his invasion of Ukraine in February last year.
One of the main reasons Nato is proving to be so reluctant to provide Ukraine with a clear timeframe for membership is the stiff opposition the proposal has received from the Biden administration.
Prior to the summit, US President Joe Biden made his opposition to the proposal perfectly clear, declaring that he did not believe Ukraine was "ready for membership in Nato", and pointing out that there was no unanimity within the alliance "about whether or not to bring Ukraine into the Nato family now, at this moment, in the middle of the war."
In public, US President Joe Biden is keen to give the impression that he is fully committed to backing Ukraine's battle for survival. But it is a different story behind-the-scenes, where Biden and his senior officials are more interested in ending the war in good time for next year's US presidential election contest.
Consequently, rather than upsetting the Kremlin by openly backing Ukraine's Nato membership bid, the Biden administration's real objective is to explore possible options for ending hostilities this year.
Biden's obsession with ending the conflict helps to explain the recent initiative undertaken by a delegation of high-ranking US foreign policy experts and former national security officials to hold secret talks with Russian Foreign Minister Sergey Lavrov in New York in April.
The aim of the meeting was to lay the groundwork for negotiations to end the war in Ukraine. Among the subjects discussed were some of the thorniest issues of the conflict, such as the fate of Russian-occupied territory such as Crimea that Ukrainian forces have not been able to liberate.
White House officials claim the American delegation, which was led by Richard Haass, a former diplomat and outgoing president of the Council on Foreign Relations, acted with the knowledge of the Biden administration, but not at its direction, and later provided US National Security Council officials with a full breakdown of the discussions.
Other members of the delegation included Europe expert Charles Kupchan, Russia expert Thomas Graham and Mary Beth Long, a veteran of both the CIA and the Pentagon.
That such a high level delegation has been authorised by the White House to open communications channels is the clearest indication yet that the White House wants a negotiated end to the conflict. It also helps to explain why the Biden administration, together with prominent European allies such as Germany and France, have been so reluctant to publicly back Ukraine's Nato membership bid.
One of the reasons Zelensky was so keen to secure a firm commitment from Nato leaders in Vilnius was because, if Ukraine were given cast iron guarantees that it could join the alliance, it would be impossible to make the issue of Ukrainian membership of Nato a bargaining chip in future negotiations with Russia.
By denying Kyiv this privilege, the Biden administration is keeping its options open, raising the possibility that the White House could be prepared to sacrifice Ukraine's hopes of joining the alliance in return for securing a deal with Moscow.
Such a deal would be nothing short of a sell-out of the Ukrainian people, and their heroic fight to protect their country from Russian aggression.
Con Coughlin is the Telegraph's Defence and Foreign Affairs Editor and a Distinguished Senior Fellow at Gatestone Institute.
Nicholas Papadopoulos