April 30 marks the 45th anniversary of the fall of Saigon at the end of the Vietnam War, although the famous picture of the evacuation from the rooftop of the American embassy was taken the previous day, on April 29, 1975.
The anniversary will pass without much global attention – in part because much of the world's gaze is fixed on the present-day Covid-19 crisis – although it has been pointed out that more than 58,000 US servicemen died or are missing in action in Vietnam, while more than that number of people in the US have so far lost their lives to the coronavirus. To put those numbers into historical perspective, more than three million Vietnamese died in the same conflict.
Another anniversary from another conflict – the "war to end all wars" – went by quietly last week.
The 105th anniversary of the first deadly use of chemical weapons during the First World War at the Second Battle of Ypres was on April 22. The moment was observed with dignity at the Menin Gate Memorial to the Missing in Belgium, with the Last Post being played through the streets of a town in lockdown.
It is worth recalling the events that sparked such sombre remembrance.
Historical accounts of April 22, 1915 suggest that those soldiers fighting on the Western Front woke to the kind of cloudless skies that many of us seem to be living under today.
It was warm, too, especially so for a northern European spring day in Ypres and, crucially, a fresh breeze softened the sunshine. A strange sound announced the beginning of the chemical weapons attack late that afternoon.
According to George H Cassar's 2010 book, Hell in Flanders Fields, "French troops heard a loud hissing noise coming from the German lines. As it continued, they saw an approaching greenish-yellow cloud".
The coloured fumes, which were later found to have been the product of more than 160 tonnes of pressurised liquid chlorine, initially caused confusion among the ranks of soldiers: some thought them to be a smokescreen that had been set up to mask oncoming German troops, others believed it to be the discharge from spent munitions.
Both assumptions quickly unravelled as the smoke drifted towards a trench manned by Algerian soldiers, part of the so-called Army of Africa branch of the French military, in which men from Morocco and Tunisia also served.
Within seconds, Cassar continues: “The men choked, their eyes and lungs burned and they were gripped by violent nausea and stabbing pains in the chest.”
As the smoke moved on, other troops spilled out of the trenches and tried to outrun the cloud, but the wind was by then too strong for them. It was a horrific scene. Around 1,000 soldiers died in the attack.
Far from creating moral outrage, the incident propelled an intense arms race.
An estimated 100,000 tonnes of chemical weapons were used by both sides before the war ended in 1918, by which time the death toll from gas attacks ran into the tens of thousands, with at least a million more injured as a direct result of their use.
Later this year, the 95th anniversary of the accord that was designed to prevent their further use was signed, although the Geneva Protocol of June 1925 and its successors, including the 1997 Chemical Weapons Convention, have sometimes proved a blunt sword to wield.
Despite the horrors of Ypres in 1915, chemical weapons remain a persistent and pernicious feature of the Syrian conflict.
In August 2013, a chemical weapons attack by Bashar Al Assad's regime in Ghouta appeared to be the moment when inertia within the international community over the civil war would be replaced by action.
Instead, the then US president Barack Obama and other prominent members of the international community walked their way back from possible confrontation by talking dismissively of "someone else's civil war" that they had no right to meddle with. Clear red lines were blurred in the prevarication.
As in Europe in 1915, the events in Syria seven years ago produced the opposite result to the one the situation compelled.
The abuses have continued, despite the Assad regime agreeing to dispense with his chemical weapons in the aftermath of the Ghouta attack.
The country's stockpile was said to have been destroyed by 2014, but the list of chemicals that have been used in Syria since then reads like a roll call of terror: sarin, chlorine and white phosphorus.
Earlier this month, the Organisation for the Prohibition of Chemical Weapons categorically confirmed that Syrian regime forces repeatedly attacked Ltamenah, a rebel town, in 2017 using chemical weapons under orders that could only have come from the top. There have been many other incidents, too.
Mr Al Assad's Syria is a broken country that will take decades to reconstruct when the war ends. When that moment comes, truth and reconciliation represent the only way through the smouldering rubble. The actions and verifications of the OPCW and others will prove crucial.
Those who perpetrated illegal acts must be brought to justice. Their crimes must be recounted. Their punishment must reflect the severity of their actions.
The only way forward is to match barbarity with the rule of law. Some of that process is currently under way at a trial of two former Syrian intelligence officers in Germany, who are accused of torture.
While their trial is a small piece in a vast jigsaw, it is still a signal that the path to reconciliation among a fractured society can only be found through truth and justice. It is also a sign that only by confronting the past and breaking the anguish of the present can the future be truly realised.
Nick March is an assistant editor-in-chief at The National