Sen. Tim Kaine (D-VA) wonders: “Is there any doubt that America would view a foreign nation firing missiles at targets on American soil as an act of war?” His question might be pertinent to why the Singapore summit happened, and what, if anything, was changed by it. The question certainly is relevant to constitutional government as it pertains — if it still does pertain — to war.

Kaine was responding to a 22-page opinion the Justice Department’s Office of Legal Counsel issued 12 days before the summit. The opinion concerns the president’s order for the April 13 air strikes against facilities associated with Syria’s chemical weapons, after the use of such weapons in a Damascus suburb. The OLC argues that the presidential order, issued without authorization by or consultation with Congress, was nevertheless lawful because the president “had reasonably determined that the use of force would be in the national interest and that the anticipated hostilities would not rise to the level of a war in the constitutional sense.”

Kaine describes as “ludicrous” the principle that presidents “can magically assert ‘national interest’ and redefine war to exclude missile attacks and thereby bypass Congress.” The OLC’s capacious definition of actions in the “national interest” encompasses “protection of U.S. persons and property,” “assistance to allies,” “support for the United Nations,” “promoting regional stability,” prevention of a “humanitarian catastrophe,” and “deterrence of the use and proliferation of” particularly heinous weapons.

This is perhaps germane to Singapore. There Kim Jong Un committed himself only to a process — “to work toward” the goal of “complete denuclearization of the Korean peninsula” — and processes can be interminable (e.g., the Middle East “peace process”). Furthermore, North Korea has espoused this goal for over three decades. Still, let us prematurely assume that something momentous has been achieved. And that the achievement was related to the U.S. policy of “maximum pressure,” including the threat, made vivid by deployments of impressive U.S. military assets, of the use of force by the president who, like many predecessors, feels free to act without involving Congress.

The threat of military force by an unconstrained president was underscored for Kim shortly before Singapore, when Sen. Lindsey Graham (R-SC), a confidant of this president, said of North Korea, “If they play Trump, we’re going to have a war.” He said “denuclearization” of North Korea is “non-negotiable,” and that a North Korean nuclear capability to strike America “ensures their demise”: “If [the president] has to pick between millions of people dying in America, and millions of people dying over there, he’s going to pick millions of people dying over there if he has to.”

Note the senator’s clear premise: It is for the president to “pick” between war involving millions of deaths, and peace. Congress, its arthritic knees creaky from decades of genuflections at the altar of presidential power, will be a gimpy spectator.

The OLC says it has “well over 100” episodes that support its contention that for 230 years presidents have unilaterally employed force in episodes short of “sustained, full-scale conflict with another nation.” Note well: “Sustained.” “Full-scale.” “With another nation.”

The OLC notes that even the 1973 War Powers Resolution, by which Congress attempted to circumscribe presidential war-making discretion, allows presidents to introduce U.S. forces into hostilities for at least 60 days without congressional authorization. Still, the OLC acknowledges that presidents must “resort to Congress” for approval of hostilities “which reach a certain scale,” involving U.S. troops in “significant risk over a substantial period.” “Certain” scale. “Significant” risk. “Substantial” period. There can be “substantial” deployments (e.g., two years enforcing a no-fly zone, and 20,000 ground troops, in Bosnia) and engagements more violent than April’s Syria episode (e.g., the U.S.-led 2011 air campaign in Libya lasting more than a week and involving more than 600 missiles and precision-guided munitions) without “war in the constitutional sense.”

The Supreme Court has said that “long settled and established practice is a consideration of great weight in a proper interpretation of constitutional provisions regulating the relationship between Congress and the president.” Regarding unilateral presidential use of military force, the OLC notes a “long continued practice on the part of the executive, acquiesced in by the Congress.”

Perhaps this got Kim nervous, and to Singapore. Nevertheless, the OLC’s meticulous argument on behalf of its client, the president, does not validate the principle that invocations of the “national interest” would legitimate a president’s decision to “pick” a major preventive war on the Korean peninsula.

© 2018, Washington Post Writers Group