For the tourism industry, bad news is often just that, leading travelers to skip a trip to the hurricane-hit Caribbean in favor of a South American destination, or pass up a tour of a historically rich country facing political turmoil.

August shootings in El Paso, Tex., where a gunman left 22 dead and injured more than two dozen others, and Dayton, Ohio, where nine were killed, had some governments warning their citizens about travel to the United States. The El Paso attack has been classified as an act of domestic terrorism, and the gunman in his manifesto said that he was specifically targeting Mexicans.

The gun violence came amid a trade war with China that has seen that country’s currency sharply devalued against the dollar, making it more expensive for Chinese nationals to visit the United States. The recent violence also coincides with the Trump administration’s contentious relationships with even some of the United States’ closest allies.

All of this has led to talk of a so-called “Trump slump” in the travel industry over the last three years, even though supporting data has been scant. But with this country’s share of the international travel market declining, experts are concerned about shifting perceptions of the United States overseas; how to keep tourists visiting America over other countries; and how to communicate that the United States is a welcoming place.