In 2008, NATO promised that Ukraine and Georgia could join the western military alliance. Russia invaded the latter four months later.
NATO meets on Tuesday to drum up much-needed support for Ukraine.
Foreign ministers from countries in the western military alliance will gather in Romania to discuss how they can assist Ukraine after Russian strikes on its power networks ahead of winter.
But the meet-up location -- Bucharest -- is hugely significant given Russia's war in Ukraine.
It was here in April 2008 that former US President George W. Bush persuaded NATO allies that Ukraine and Georgia would one day join the military alliance.
Moscow invaded Georgia four months later.
Some experts describe the decision in Bucharest as a massive error that left Russia feeling cornered by a seemingly ever-expanding NATO.
NATO counters that it doesn't pressgang countries into joining and that some requested membership to seek protection from Russia — as Finland and Sweden are doing now.
'Winter as a weapon of war'
Officials will gather over the next two days at the Palace of the Parliament in Bucharest.
NATO leaders will likely make fresh pledges of non-lethal support to Ukraine, including fuel, generators, medical supplies, winter equipment and drone jamming devices.
Ukraine's critical infrastructure has been hammered by Russian strikes in recent weeks, knocking out power and water supplies for prolonged periods of time.
Ahead of the meeting, NATO Secretary-General Jens Stoltenberg said Russian President Vladimir Putin was “trying to use winter as a weapon of war" and that Ukraine should be “prepared for more attacks.”
The Norwegian Refugee Council warned on Friday that Europe, home to the bulk of NATO's 30 members, needed to prepare for hundreds of thousands of Ukrainian refugees, saying they faced the grim choice between "fleeing or freezing" this winter.
Individual allies also look set to promise more military supplies, particularly new air defence systems that Kyiv desperately wants to protect its civilians and army.
NATO has so far been reluctant to supply Ukraine with such equipment or weaponry that can strike deep into Russian territory, not wishing to stoke a wider conflict.
Foreign ministers will also explore the future.
“Over the longer term we will help Ukraine transition from Soviet-era equipment to modern NATO standards, doctrine and training,” Stoltenberg said last week.
This will help Ukraine's armed forces meet NATO's criteria for membership and better integrate into the alliance, should it be admitted.
The chances of Ukraine joining NATO are slim in the short to medium term, with the country still at war and occupied by a foreign power.
Promises that Ukraine could join NATO 14 years ago were controversial, with Putin describing it at the time as a "direct threat" to his country's security.
In a press conference on Monday, NATO Secretary-General Jens Stoltenberg highlighted the importance of investing in defence "as we face our greatest security crisis in a generation.”
“We cannot let Putin win," he said after meeting Romania's President Klaus Iohannis.
"This would show authoritarian leaders around the world that they can achieve their goals by using military force — and make the world a more dangerous place for all of us. It is in our own security interests to support Ukraine.”