Does that look like Trump’s idea of a “big beautiful wall”? Does it even look like the “steel slats” the president now offers as his idea of an aesthetic concession to Democrats? Not quite. Yet for the last 19 years it was all the fencing Israelis thought was necessary to secure its side of the Blue Line.

That started to change in December, after Israel announced that it was conducting an operation to destroy tunnels dug by Hezbollah under the border. The tunnel construction — secretly detected by Israel some four years ago — was intended to infiltrate hundreds of Hezbollah fighters into Israel in the event of war. As an additional precaution, Jerusalem is spending an estimated $600 million to replace about 20 kilometers of the fence with a concrete wall, mainly to provide greater peace of mind to the 162,000 Israelis who live near the Lebanese border.

Such a wall may look formidable. But it won’t stop tunnel construction or missile firing, the two principal threats Hezbollah poses to Israel. Nor has Israel felt the need to erect concrete walls along most of its border with the Gaza Strip, despite Hamas’s multiple attempts last year to use mass protests to breach the fence. Israel’s border with Egypt is marked by a tall and sturdy “smart fence” packed with electronic sensors, but not a wall. And Israel’s longest border, with Jordan, stretching some 400 kilometers (about 250 miles), has fencing that for the most part is primitive and minimal.

So how does Israel maintain border security? Two ways: close cooperation with neighbors where it’s possible and the use of modern technology and effective deterrence where it’s not.