cause — a person or thing that acts, happens, or exists in such a way that some specific thing happens as a result; the producer of an effect: You have been the cause of much anxiety. What was the cause of the accident?
impose — to lay on or set as something to be borne, endured, obeyed, fulfilled, paid, etc.: to impose taxes.
occasion — a particular time, especially as marked by certain circumstances or occurrences: They met on three occasions.
tangle — to bring together into a mass of confusedly interlaced or intertwisted threads, strands, or other like parts; snarl.
give rise to — to get up from a lying, sitting, or kneeling posture; assume an upright position: She rose and walked over to greet me. With great effort he rose to his knees.