Under US President elect Donald Trump (C), the congressional GOP has its bet chance in years to see defense spending dramatically increase. EPA/SHAWN THEW

Defense hawks are quietly celebrating the election of Donald Trump  — now, they might just get more than they ever dreamed possible.

That’s because Washington Republicans and the president elect have more in common on defense spending and priorities than it might seem given Trump’s hardline foreign policy stance against immigration, his questioning of longstanding strategic alliances like NATO and support for talks with Russian President Vladimir Putin.

Trump ally Rudy Giuliani, a contender for a cabinet position, said on CNN Sunday that strengthening the military is a major priority of the president-elect.

“He’s going  to be facing Putin with a country that is not diminishing it’s military but a country that is dramatically increasing it to Reagan like levels,” Giuliani said, invoking the Reagan mantra of “peace through strength.”

Trump and congressional Republicans are actually on the same page on a host of defense priorities, including increasing the number of active duty troops in the Army and size of the Navy, large-scale modernization of military facilities, weapons and the nuclear arsenal; and a dramatic spike in missile defense. And Trump — despite benefiting politically during the campaign from hacks of Democratic political groups — also touts the need for improved cyber security, which is already under discussion on Capitol Hill.

“This is all music to the ears of not only Republican leaders in defense, but many Democrats too,” said Michael Herson, a prominent defense lobbyist.

Trump’s team hasn’t laid out all the specifics yet on defense policy, which will be largely implemented by his defense secretary . A figure like Sen. Jeff Sessions (R-Ala.) or Gen. Michael Flynn – both Trump campaign surrogates – could mean a different Pentagon than if the military establishment was headed by former Bush administration adviser Stephen Hadley, or an establishment hawk who has criticized Trump like Sen. Kelly Ayotte.

The biggest obstacle to enacting a wide-ranging host of GOP defense priorities is the cost — according to an estimate from the American Enterprise Institute’s Mackenzie Eaglen and Rick Berger, anywhere from about $100 billion to $300 billion more over the next four years than President Obama’s current plan.

Congress can’t legally spend that money until it gets rid of budget caps as part of the sequester holding spending check since the start of fiscal 2013. Trump called for the end of those budget caps on the campaign trail, promising he would “ask Congress to fully eliminate the defense sequester and will submit a new budget to rebuild our military,” during a September speech in Pennsylvania.

House Armed Services Committee Chair Mac Thornberry (R-Tex.) “is encouraged by the president elect’s determination to rebuild America’s military, a priority that Chairman Thornberry shares,” his spokesman Claude Chafin said.

So, apparently, are the markets: defense stocks spiked considerably the day after Trump’s election — with the stock value of some of the biggest defense contractors like Northrop Grumman, Raytheon and Lockheed jumping between more than 5 to 7.5 percent at the news.

But there is still resistance in Congress to Trump’s plans — potentially from the more fiscally conservative Republicans and Democrats.

“There is considerably more demand for defense spending than there is money to meet that demand,” House Armed Services Committee Ranking Member Adam Smith (D-Wash.) said the morning of the election. “Look at all the programs that are out there, from the B-21 (bomber) to upgrades to our submarines, upgrades to our arsenal, to rising personnel costs – add it all up and it is vastly more money than we’re going to have. How do you deal with that?”

Under a Trump administration, finding a way to lift budget caps depends on whether lawmakers and the president-elect can agree on a series of tax reforms and entitlement cuts, both of which could spark intraparty conflict. For example: Trump the populist promised not to touch Social Security benefits, which are limited under House Speaker Paul Ryan’s (R-Wis.) fiscal plan.

Progress is more likely on defense priorities because Republicans believe Trump is unlikely to adopt the Obama administration’s stance that every dollar of discretionary defense spending be matched by a dollar of discretionary domestic spending, which covers  such programs as food stamps, community development and education programs, and transportation and infrastructure.

Thornberry has frequently complained that Democrats’ insistence on parity between domestic and defense spending effectively means defense budgets are “held hostage” to non-defense spending.

The GOP argues that means the military must choose between rehabilitating planes so old they are running on scraped-together “museum piece” replacement parts and a credible missile defense; or between giving over-taxed and under-equipped soldiers a reasonable number of training hours and funding operations against the Islamic State.

Republicans have sought to get around this by demanding emergency war funds – which are not subject to budget caps — to cover certain defense spending. Democrats have repeatedly decried the tactic as a sneak attack to let the GOP avoid tough budget negotiations to end sequestration.

If the sequestration hurdle is cleared, Washington’s leading defense hawks are betting they start to see defense get a long-needed influx of cash.

“Nobody gets a blank check,” Herson said. “But I think we get the infusion we need to restore our strength.”

The first targets for an increase would be infrastructure and materiel upgrades, replacing legacy systems, and boosting the military’s recruitment program, which are already Republican priorities. Then could come some of the priorities Trump has identified — such as ramping up thew Army up to 540,000 soldiers and increasing the Navy’s fleet to 350 ships — and, Republicans hope, increasing procurement dollars for next-generation bombers and missile defense.

Trump has proposed cutting non-defense spending by about one percent a year, which could make way for more military investment. A recent estimate from the Center on Budget and Policy Priorities found that under Trump’s plan, by 2026, spending on non-defense programs would drop by anywhere from 29 to 37 percent.