And how well have we calculated the many problems and difficulties in reconstructing Iraq's government once Saddam Hussein is removed?
"This statement will create problems and difficulties for the bilateral relations between Pakistan and America," Ms. Awan said.
In most cases the causes of poor mental health tend to be a combination of work problems and difficulties people are experiencing outside work.
The company, which has had cash-flow problems and difficulties with recent expansions, closed 43 Big Boy Restaurants in Pennsylvania, West Virginia, Ohio and Michigan last month.
The charity highlighted the debt problems and difficulties accessing in-work benefits for the millions of people who do not have fixed, regular working hours.
Then there are issues such as inadequate or inappropriate skills, housing stress and homelessness, health problems, and difficulties accessing transport or childcare.
("Can you believe that, with all of the problems and difficulties facing the U.S., President Obama spent the day playing golf. Worse than Carter," he tweeted in 2014).
Collecting big things, like (say) historic utility poles, or used truck tires, is liable to create practical problems and difficulties in the family.
So McCain made it clear that if he had been in Washington, he would have voted no because the bill "opens us up for lawsuits, for all kinds of problems and difficulties".
But despite his eye problems and difficulties in walking that remain after hip replacements, it is impossible to get him to complain, and almost equally impossible to lure him into reminiscences about his eventful life.
A report produced by Somerset council last year highlighted problems including some missed targets, IT teething problems and difficulties in establishing a level of loyalty from transferred staff, although its customer contact centre and management spending controls were praised.
