Russia's president, Vladimir Putin, welcomed US secretary of state John Kerry to the Black Sea resort of Sochi today, but its sunshine and spring flowers were at odds with the mood around the meeting.
Last weekend, Putin oversaw Russian commemorations of the end of the second World War, which were notable for the country’s biggest-yet military parade and the intense patriotic fervour whipped up by officials and state media.
As troops, tanks and nuclear missile launchers rumbled past the Kremlin and military aircraft roared overhead, the blunt message was that Russia’s resurgent armed forces would never be intimidated, let alone defeated.
Western leaders declined to attend, finding it impossible to watch Putin triumphantly brandish his military might while they accuse him of sending troops and weapons into eastern Ukraine to support pro-Moscow separatists.
Red Square reverberated to heavy armour as the diplomatic tone again darkened around developments in Ukraine and prospects for a ceasefire deal, initially agreed last September and revised in February.
"It does appear that, clearly, Russian-backed separatists in eastern Ukraine are preparing for another round of military action," US defence secretary Ashton Carter said last week.
Days earlier, the US military commander of Nato, Philip Breedlove, said Russian and militant forces had used the supposed ceasefire to "reset and reposition themselves . . . These preparations are consistent with the possibility of an offensive."
This week, Nato secretary general Jens Stoltenberg said Russian and rebel forces could now "launch new attacks with very little warning time".
Kiev says militants have taken full or partial control of at least 28 towns and villages since the February ceasefire, and more than 100 government soldiers have been killed, with more than 500 wounded in the same period.
Washington accuses Moscow of helping the rebels to steadily expand their territory, and insists Ukraine is acting defensively; the EU is less critical of Mr Putin but regularly urges him to do more to stabilise the conflict zone.
Moscow and the militants accuse Kiev of constant ceasefire violations and of doing nothing to fulfil the terms of the truce agreement.
None of the deal’s key measures has been fully implemented.
International monitors report daily artillery fire and violations by both sides of restrictions on the location of heavy weapons. In addition, a full prisoner exchange has not occurred; Kiev and the rebels disagree over decentralisation reform; state benefits are still not being paid in separatist territory; and plans for local elections in the east are deadlocked.
Crucially, the border between Russia and the rebel- held areas remains wide open. Moscow says it will not let Ukraine control its own eastern frontier until rebels are happy with constitutional reform and local elections – effectively giving the militants and their Russian masters a veto over Ukraine's national security.
Moscow and the separatists still demand a federal Ukraine, which Kiev sees as a road to perpetual destabilisation by the Kremlin and its proxies. This is unlikely to change, and the ceasefire is set to keep on fraying until it rips apart.