The Senate is set to move forward with its version of the annual defense policy bill known as the National Defense Authorization Act -- marking the latest step for a key piece of legislation that has been passed by Congress for 55 straight years.
At a time where passing bills is often challenged by the deep partisan divide and competing political factions on Capitol Hill, it can be difficult to understand why the NDAA would be any different.
But as the measure that sets military policy on issues such as Guantanamo Bay, buying weapons, pay raises for service members and even the endangered status of the Sage Grouse, the NDAA is considered of one the few must-pass bills left in Congress.
So what makes it so important?
One of the most obvious reasons is the money.
The NDAA authorizes levels of defense spending -- an amount between that will total between $600 and $700 billion for the next fiscal year that begins on October 1 -- and sets the Pentagon policies under which that money will be spent.
This year's bill is expected to authorize a major hike in military spending and even exceed the $54 billion defense budget increase requested by President Donald Trump for 2018 that aimed for more aircraft and ships.
In July, the House of Representatives passed their $696 billion version of the bill which included $28 billion more in defense spending than the Trump administration requested.
The Senate's bill is expected to authorize a similar amount based on the mark up completed by the armed services committee, led by Arizona Republican Sen. John McCain, in June.
If the Senate's bill passes as expected then both houses of Congress will come together to vote on a final version. A vote in the Senate is scheduled Monday.
But the fight over the size of the defense budget is just getting started, however, as Senate Democrats have vowed to block major increases to defense spending without equal increases to domestic programs.
That fight will occur later this year over the defense appropriations bill, which is a separate piece of legislation that allocates spending for the Pentagon.
In addition to authorizing increased military spending, the NDAA will set Pentagon policy on several key issues including troop level increases for the service branches and render a decision on a controversial new "Space Corps" program that was included in the House version of the bill but left out by the Senate.
The program was also opposed by the White House and the Air Force.
There will also be several controversial issues that will likely be left out of the NDAA including an amendment that would block Trump's ban on transgender service members and the proposed repeal of the 2001 and 2002 war authorizations that the US military uses to fight terrorism across the globe.
