Tony Blair knows public opinion can be a fickle friend. So it was perfect timing which saw him at the National Assembly in Wales yesterday delivering his "Never Forget" message to the British people.
For the immediate backdrop was an ICM poll showing a sharp drop in support for the American-led war against Afghanistan's Taliban regime and, for the first time, a majority actually favouring a pause in the bombing to allow aid convoys into the country.
There is, as yet, no threat to Mr Blair's position. The British public have not suddenly defected to the anti-war party. The poll showed those opposed to military action had only increased by four percentage points (from 16 per cent to 20 per cent) over the past four weeks, while 74 per cent continued to back it.
However, a slump in support among women, down 17 points from 68 per cent to a bare 51 per cent majority - and a similar marked decline in support among older voters - will have reinforced the message already hitting Downing Street that concerns about civilian casualties and the gathering humanitarian crisis spell volatility and serve as warning against any tendency to presume upon public acquiescence.
As in America, so here: it was perhaps inevitable. Since the horrific events of September 11th opinion poll ratings for Mr Blair, like those for President Bush, have been approaching the stratospheric. Not even these two war leaders could have believed themselves immune to the iron law of politics which decrees that which goes up must sooner-or-later come down.
Moreover, British ministers - most vocally the Foreign Secretary, Mr Jack Straw - have been increasingly worried by, and critical of, a 24-hour news industry whose relentless search for novelty and the fresh angle can, in their view, provide undue focus on short-term setbacks and internal dissent while fuelling popular impatience for speedy results.
There may have been headline-catching differences of emphasis on both sides of the Atlantic from politicians and soldiers pondering whether this war would last weeks, months, years or even a lifetime. However, neither Mr Blair nor Mr Bush promised any quick fix when they commenced the military action just over three weeks ago. And that the Prime Minister should feel moved so soon to seek to stiffen public resolve is itself eloquent testimony to the hazardous course on which he is embarked and the truly "testing times" which may lie in wait for him and his government.
One additional factor possibly at play here, identified by Hugo Young in yesterday's Guardian, may be that while the British can feel America's pain they did not actually share it. Britain wasn't a target on September 11th and it might just be that "this omission weakens the war's hold on the British gut". It was to that gut-British instinct that Mr Blair appealed yesterday: "It is important we never forget why we are doing it. Important we never forget how we felt watching the planes fly into the twin towers. Never forget those answering machine messages.
"Never forget how we felt imagining how mothers told children they were about to die."