"It has become much more difficult to smuggle dangerous substances across our borders over the past three years, and this is creating real problems for drug traffickers"

In this quote, John Walters is highlighting the increased problem in smuggling unsafe compounds throughout borders recently. This has actually created considerable difficulties for drug traffickers who count on these illegal activities for profit. Using the word "smuggle" recommends that these substances are being transported in secret and without appropriate permission, showing the illegal nature of the activity. The mention of "our borders" indicates that Walters is speaking from the point of view of a federal government or law enforcement authorities, and using "our" suggests a sense of ownership and obligation for safeguarding these borders. In general, the quote recommends that efforts to reinforce border security have actually been successful in interfering with the operations of drug traffickers.