These British friends were tracking the supply of armor piercing explosive devices known to be coming from Iran. If smuggling those devices into Iraq isn't state sponsored terrorism, what is?
For the present, it is necessary to seal the border from this activity. Iran knows what is expected by the governments of the world to maintain stability and join the rest of the civilized nations. Drop their nuke program, stop supporting terrorists, stop being a pain in the neck to the rest of the world.
If we need to rattle their cage to encourage Iran's citizens to change their leadership, sealing the border from terrorism trade to Iraq is a good way to start.
All great things are simple, and many can be expressed in single words: freedom, justice, honor, duty, mercy, hope.
Sir Winston Churchill
"Here's my strategy on the Cold War: We win, they lose."
Ronald Reagan
Victory at all costs, victory in spite of all terror, victory however long and hard the road may be; for without victory there is no survival.
–Winston Churchill