IF IT IS TIME, TAKE COMMAND
Robert Benchley, a humorist who died in 1945, said, "Drawing on my fine command of language, I said nothing."
Declarer is in total command of his side's forces; he fights the battle alone. The defenders usually work together to defeat a contract; rarely does one defender take total command and leave his partner playing third violin, just trying not to renege.
Which applies in this deal? West leads the heart queen against South's contract of three no-trump.
South's jump to game indicated a balanced hand with a good 12 to 15 points, typically at least two stoppers in the intervenor's suit and fewer than four spades because he did not make a negative double. North had no reason to believe that five clubs would be better. (Note that that contract goes down if East leads a heart, or cashes a high trump and shifts to a heart at trick two.)
South has six top tricks: three spades, one heart and two diamonds. He will get a second heart winner, but must establish dummy's clubs, which involves losing the lead twice. He is in jeopardy.
A meek East would signal exuberantly with the heart 10 at trick one. Then, after South played low, East would sit back and wait ... and wait ... and wait ... for partner to lead a second heart. Probably West would shift to a spade, but now South would get home with an overtrick.
A more commanding East will see that he is getting on lead twice in clubs. He will overtake the heart queen with the king and continue the suit should declarer duck. Now the contract goes down.
If you see how to defeat a contract, take command.