As recently as a generation or two ago, the mainstream of American politics observed an important limit whereby domestic politics did not operate beyond the nation’s boundaries.  This did not mean there weren’t sharp differences and vigorous debate about foreign policy, often along party lines.  There always have been those, going back to differing Federalist and Democratic-Republican sentiments toward Britain and France in the early days of the republic.  The limit was nonetheless based on recognizing a common national interest in America’s encounter with the rest of the world, and on believing that this interest takes precedence over more parochial and partisan interests.  Flowing from this recognition was a felt need to present a single face to the outside world and to avoid washing dirty domestic political linen on foreign soil.

The limit also included the concept that party lines should not cross, in either direction, the nation’s boundaries.  This concept has been even stronger in the United States than in most European democracies.  There has been a traditionally American aversion to participation in transnational partisan movements such as the Socialist International, and not just because that particular movement is socialist.

In modern times one of the foremost personifications of this limit was Republican Senator Arthur Vandenberg, who, as chairman of the Senate Foreign Relations Committee, worked with the Truman administration in establishing the post-World War II international political and economic architecture.  His role included active participation and not just Congressional approval; Vandenberg was, for example, a U.S. delegate to the founding conference of the United Nations.  The guiding principle of Vandenberg’s conduct on these issues was, in his words, that “we must stop partisan politics at the water’s edge.”

Today one can find discouraging examples of disdain for Vandenberg’s principle.  There was, for example, the egregious open letter to Iran three years ago that Senator Tom Cotton of Arkansas devised, most Senate Republicans signed, and basically said to the Iranian regime that it should not take as a credible commitment whatever the incumbent U.S. administration was saying at the negotiating table.

This month we have had another demonstration of how far things have come from Vandenberg’s principle in the form of Vice President Mike Pence’s trip to the Middle East.  The trip also demonstrated how, on one foreign policy issue in particular, the principle had been abandoned some time ago even though many on one side of that issue do not want to admit it.

Early in the trip Pence held a meet-and-greet with U.S. troops at an undisclosed location near the Syrian border.  This sort of meeting with American service members overseas is traditionally a way for senior leaders to express, on behalf of themselves and the American people, appreciation for the troops’ work and sacrifices.  It is supposed to be an apolitical morale booster.  It is one of the last places where partisan attacks should intrude.  But Pence used the occasion to lambaste Democrats for the government shutdown.  Senior staffers for previous vice presidents, both Republican and Democratic, appropriately criticized Pence for his very inappropriate abuse of the occasion.

Then came Pence’s speech to the Israeli Knesset.  Pence—notwithstanding his performance from time to time of clean-up duty back home after some of Donald Trump’s rhetorical excesses—did nothing to limit the damage from Trump’s recent divisive proclamation regarding Jerusalem.  Instead, Pence exacerbated the damage.  He went all in with the Israeli right wing, who could not have loved the speech more if the Israeli prime minister’s office had drafted it.  One of the leading hardliners in the ruling coalition, Naftali Bennett, said the speech “will go down in the history books of both nations.”

The most plausible interpretation of Pence’s primary motivation in designing the speech, replete with biblical references, was that he was speaking to American evangelical Christians whom Pence considers his primary domestic political base and of whom he is himself a member.  Domestic political considerations (supplemented by personal religious sentiments) took precedence over well-considered conduct of relations with a foreign country, and did so in a way that advanced neither U.S. interests nor international peace.  That Pence was aiming his remarks at American Christians, not Christians in the Holy Land in which he was speaking, was reflected in how the latter were unsurprisingly critical of Pence for buying into the Israeli government position.

Pence’s totally taking one side of a bitter conflict inside Israel and inside the Holy Land was further reflected by reactions to the speech within the Knesset.  While right-wingers were joyfully singing along with this music to their ears, MKs belonging to the Joint List, which predominantly represents Arab Israelis, held up signs in protest before they were ejected from the chamber.  Whatever one may think about this protest, Pence’s reacting to the interruption by referring to Israel’s “vibrant democracy” was an insult, given that the lack of political rights of millions of Palestinian residents of territory Israel occupies is at the heart of what makes the conflict at hand so bitter.

Political divisions over there are increasingly linked to political divisions over here.  A new Pew survey of American public opinion shows a continued increase in partisan divisions in attitudes toward Israel and toward the Israeli-Palestinian conflict.  Staunch support for Israel has become increasingly identified with the Republican Party; questioning of Israeli policy is to be found much more in the Democratic Party.

Putting this whole picture together, we have more than just partisan differences over foreign policy; again, the United States has had plenty of that since its earliest days.  We have a departure from the traditional limits in which internal political divisions were not permitted to cross the national boundaries, in one direction or another, to determine politics and policies on the other side of the boundary.  There exists today what amounts to a two-nation Likud International, which is determining policy in both Israel and the United States toward the Israeli-Palestinian conflict.  Of course, it is not called the Likud International and there are several strands, including Pence’s evangelical Christianity, that weave into it on the American end.  But the nature of the political dynamics involved, and the end result, befit the name.

If there is a positive side to any of this, it may be to lay ever more bare, and to make obvious to more people than ever before, that the direction of U.S. policy on this issue has had far more to do with domestic politics and cross-boundary political intrusion than with any dispassionate and nonpartisan analysis of what would be in U.S. interests.  As with any other foreign policy issue, violation of the traditional American limits about national boundaries and political phenomena that should not cross them does not serve American interests well.  Arthur Vandenberg would have understood.