The US Congress is approaching its favorite time of year, August recess, when members flee the oppressive heat and humidity of Washington. Get ready, Israel, they are coming to a handshake near you.Congressional recess periods allow members to travel home to their communities or around the world. Although the latter are maligned as “junkets,” they are critical to informing judgments about global issues. Reading a briefing about the Iron Dome anti-missile defense system is one thing; seeing it in action is another. Attending a classified briefing about the wars in Iraq and Afghanistan is helpful to congressional decisions on funding the military, but going into the military theater and discussing it with the people doing the fighting is priceless.Israel is a popular destination for congressional travel, and not just for the photo ops and falafel. It is Congress (not the president) that appropriates funds, decides on levels of foreign military financing, and allocates money for Israel’s ballistic missile defense and other vital technologies. The House and Senate appropriations committees are considered two of the most powerful committees on Capitol Hill for a reason: They spend the money.As a member of the House Appropriations Committee, I visited Israel with my colleagues countless times. One of the most important was in the days immediately following Hamas’s rocket attacks in August 2014. We were the very first congressional delegation to arrive.Just a few days before, Congress had granted president Barack Obama’s emergency request for $225 million to help replenish Israel’s Iron Dome stockpiles. This wasn’t a vote to be taken lightly. There were deep economic anxieties at home; many American media outlets were reporting critical stories about Israel, and controversy was building over the Iran nuclear deal.Our visit included briefings on the effectiveness of Iron Dome. From the Golan Heights, we saw – without binoculars – plumes of smoke from rocket exchanges between rebel and government forces in Syria. We learned about the extensive network of tunnels penetrating Israel’s soil near the Gaza Strip.Every member of that congressional delegation returned home with a deeper understanding of Israel’s needs. In fact, that particular visit inspired me to work with Rep. Gwen Graham (D-Florida) to successfully secure $40m. in tunnel-detection technologies for Israel. Still, the most compelling congressional visit I made was soon after my 2000 election. I came on a trip organized for new members by the AIPAC Educational Foundation.Most of my colleagues had never been to Israel. They represented vast rural districts practically the size of Israel. Their preconceived notion was that yours is a big country that could afford to give up some land.One day, we traveled to a high point. Our guide pointed east at the mountains and said: “That’s the West Bank.” Then he pointed west at a distant and vaguely discernible skyline and said: “That’s Tel Aviv.” One of my colleagues said: “Well, how can we expect these people to give up land when you can see from one end of the country to the other? I can’t see from one end of my district to the other!” Putting aside individual views about the peace process, that visit offered a view of the terrain. On that congressional visit, as with all others, I learned the indispensable lesson of persuasion: Seeing is believing.The writer served in the US House of Representatives from 2001 to 2017 and was a member of the House Democratic Leadership. He currently serves as chairman of the Global Institute at Long Island University.