And a fortnight ago, the pope, during a visit to the US that may have reset political debate, spoke of the moral imperative of tackling climate change.
In China, an economic slowdown caused by the imperative of tackling a dangerous debt bubble - what I've discussed in this column as the important third-phase of global rebalancing - has not made the government any more tolerant of a hunger in some parts, especially Hong Kong, for greater economic freedoms.
Mr Lamb said it was important to weight "the imperative of tackling climate change" against the need to maintain trade links with the developing world.
But from the broader perspective of her campaign, the imperative is that she taps into the deep economic insecurity that many Americans feel, and that she is seen to have a credible and sensible agenda for tackling it.
Wider responsibilities for tackling unemployment.
Therefore, the need to measure and take into account QoL in infertility is imperative and tackling this measurement hurdle could lead to improved patient outcomes.
"I've been hearing from my Republican friends for quite some time that it is a moral imperative for us to tackle our debt and our deficits in a serious way," Mr. Obama said, in what could be read as a reference to Mr. Boehner's April speech.
In his Monday press conference, Obama advanced the ball further, telling reporters: "I have been hearing from our Republican friends that it's a moral imperative for us to tackle our debates and deficits in a serious way.
The neglect is most extreme in energy, where chronic underinvestment is now twinned with another pricey imperative: tackling climate change.
We believe it is imperative to tackle excessive pay not just for the greater good of society but for businesses and the health of the economy.
