ANALYSIS — President Donald Trump’s defense budget request is sparking partisan discord that will last for months, but the hard-fought outcome is likely to be a bipartisan accord to keep defense spending at its historically high level.

The conflict is real. A House controlled by Democrats will not easily swallow Trump’s proposal to slash spending on nondefense programs by 9 percent at the same time as he wants a nearly 5 percent increase in defense spending. Trump’s $750 billion request for the Pentagon and other defense accounts marks one of the biggest peacetime defense budgets since World War II, even adjusting for inflation.

Secondly, a bipartisan chorus has derided Trump’s ploy to circumvent the defense budget cap in law by requesting $97.9 billion for assorted defense programs unrelated to war in the warfare account (known as the Overseas Contingency Operations budget), which is the part of the Defense Department budget that is exempt from the statutory spending limits.

Not least, Trump’s request to use about $7 billion in “emergency” (meaning: uncapped) Pentagon money for building barriers on the U.S. southern border is about as contentious an idea as possible.

Getting through fierce fights on these issues will be a painful process — one that may not conclude until deep into fiscal 2020. Other bitter tussles will take place over weapons programs and Defense Department personnel issues.

“There are a lot of moving parts at work this budget season, so this is going to be a long, protracted battle,” says Todd Harrison, a defense budget analyst with the Center for Strategic and International Studies.

Also watch: Why presidential budget requests are usually dead on arrival, explained

COLA for the Pentagon?

Yet, when the grueling marathon ends, the upshot is likely to be a massive defense budget, most experts say.

Gordon Adams, a former Office of Management and Budget official, thinks the final fiscal 2020 appropriation for defense will end up somewhere near $733 billion, as does Harrison — about a 2.4 percent increase over the current level, or half the amount Trump wants.

That may be a cost of living adjustment — enough to keep pace with inflation, but not much more — which sounds grim, except that the baseline for that increase is so high.

Mark Cancian, another former OMB official who is also an analyst with the CSIS, predicts Democratic pressure will leave the final funding measure between $716 billion, the fiscal 2019 level, and $733 billion.

All agree however, that getting to “yes” this year will be harder than in previous budget battles.

Political trench warfare

Trump’s request for new money for border barriers will be hard to come by and Democrats will fight tooth and nail against his request for funds to refill military construction and other accounts that he has sought to raid in fiscal 2019 for wall money.

Democrats will push, too, for limiting any president’s authority to circumvent Congress in the future in this way.

Given the charged nature of the debate, it could be longer and thornier than usual.

The primary struggle in Washington in 2019 will once again be over the issue of the budget caps in law. The decision on the caps will be made by the top four congressional leaders, probably in late 2019 if not in early 2020, and perhaps only after one or two continuing resolutions are adopted.

“Ultimately, the politics here is going to be determined at the leadership level,” Adams said.

Congressional aides have predicted that the debate over the authorization bill, or NDAA, which sets policies, will be hung up in the meantime as Armed Services members will probably not know the money they are authorizing until the 11th hour.

There is reason for hope that a budget deal will occur. For each fiscal year since the defense and nondefense budget caps were enacted in fiscal 2012, Congress has raised both of them.

There is no reason to believe fiscal 2020 will be different, except perhaps in how acrimonious the process of getting there may become.

The Democrats’ hand is strengthened this year because of their newfound majority in the House. That suggests there will be a more-than-usual amount of downward pressure on defense spending, along with more upward pressure on nondefense appropriations.

Democrats’ stronger position means, at a minimum, that any increase to the defense cap will be matched by a nondefense increase — if not dollar for dollar, then close.

Numbers game

The challenge for lawmakers is in black and white. In fiscal 2019, the defense base budget cap was $647 billion, and it is due to drop to $576 billion in fiscal 2020, a $71 billion reduction. (The Pentagon gets about 96 percent of that total.)

Trump is going along with that base budget drop. But he wants to boost the defense budget via the overseas account.

The Pentagon overseas account stands at $69 billion this fiscal year, and Trump would only slightly shave that part of the overseas account, requesting about $66.7 billion.

But the president would prefer to pad the overseas account significantly — bringing it all the way up to $165 billion — by including the $98 billion increase that is actually for non-war programs.

That sleight of hand would more than make up for the $71 billion in looming base budget cuts.

Trump’s budget request also includes about $9 billion for other emergencies, most of which is for southern border barriers.

Most experts do not think Trump will succeed in getting the $750 billion, no matter how it is apportioned among accounts.

If he does get some amount close to $733 billion, as most experts predict, he will have received the amount the Pentagon had planned to seek before a last-minute December decision by Trump to request $750 billion.

In other words, Congress is expected to go along most of the way toward Trump’s defense budget target, even as lawmakers differ sharply with his way of getting there.

Capitol Hill will probably put in the base budget about $80 billion or so of the $98 billion Trump wants to wedge into the overseas budget, Cancian predicted.

But members will have to get the caps raised to do that.

To the extent Republicans will resist nondefense cap increases to go along with the defense cap hike, the disagreements will be fierce. But they have been rough-and-tumble affairs every year since fiscal 2012.

The wild card, of course, is Trump. The question — which may not be answered until Oct. 1 or later — is how far will he go to hold the line on nondefense spending increases and, specifically, whether another government shutdown may be part of the negotiations.

Cherry-picking

A nearly 3 percent raise over the current level to $733 billion is probably enough to keep pace with inflation. It is not the 5 percent annual increase that some hawks have called for, but that is probably not a politically feasible objective anyway.

Even so, a $733 billion defense budget would still be the highest since World War II, save for the height of the Iraq and Afghanistan wars.

The “cuts” that will be made to Trump’s budget request to go from $750 billion down to $733 billion or thereabouts may for the most part be reductions below what the president proposed for some programs, not actual declines in spending compared to fiscal 2019.

It remains to be seen what will have to give in order to shave a few percentage points off the proposed increase in the total amount of defense funding.

“It’s hard to know which of those cherries on top of the cake are going to be taken away,” Adams said.

Accounts that cover personnel, infrastructure, maintenance and training are, to varying degrees, more difficult to scale back than spending on developing and procuring weapons and services.

Investment account is where the battle is going to be because “there just isn’t a lot of latitude elsewhere” in the budget, Cancian said.

The Pentagon is clearly adding money for more cutting-edge weapons such as hypersonic vehicles and unmanned ships and is scaling back procurement of some other ships and planes in the process.

But Congress will have its own strong ideas about all of those details, just as it will about the total amount of money the Pentagon will get.