BBC News: Outside observers would be forgiven for being a little mystified at news that the US government has shut down. So what is going on and how did we get here?
When was the deadline?
A spending bill – called an appropriations bill in US political parlance – had to be passed by Congress and signed by President Donald Trump by midnight on Friday 19 January.
This did not happen, and so the federal government has effectively closed its doors.
Haven’t we been here before?
Yes, the US government has closed for business several times.
Most recently in 2013 for 16 days, when Republicans demanded the spending bill have provisions to strip funding from Democrat President Barack Obama’s Affordable Care Act or delay its implementation.
National monuments and parks were closed and hundreds of thousands of government workers put on unpaid leave. Only one person was left to patrol the 5,525 mile (8,891km) border with Canada.
Before 2013, there was a shutdown for 18 days in 1978 and two under Bill Clinton in 1995 and 1996.
But this is the first time that a budget impasse has led to a shutdown when both chambers of Congress and the White House are controlled by the same party – the Republicans.
Who put the bill together?
Hopes for a long-term spending bill, funding the US government for the entire 2018 budget year that ends in October, have long since vanished.
The measure which failed to fail to pass on Friday evening would have kept Washington running until 16 February, when the whole showdown will start anew.
It was crafted by the Republican leadership in the House of Representatives and the Senate and included a few sweeteners to make it easier to vote for (and more difficult to vote against).
Several unpopular healthcare taxes were suspended in this bill.
And the Children’s Health Insurance Programme (Chip), which provides coverage for low-income families – on the verge of running out of funds – was fully re-authorised for six years.
But these sweeteners were not sweet enough, and the bill failed to pass.
Wasn’t everything looking good for it to pass?
On Wednesday the Republican game plan seemed clear.
Pass the temporary funding, with the sweeteners, over unanimous Democratic opposition in the House of Representatives. Then essentially dare Democrats to block the bill in the Senate, denying money for poor children and forcing a shutdown.
The ground beneath the party began to crack on Thursday, however.
The president tweeted that he didn’t support the inclusion of Chip funding in the stopgap bill, forcing the White House scramble to explain that Mr Trump still backed the legislation.
The House of Representatives passed the bill, but a handful of Republicans in the Senate said they would vote no.
And the Senate Democrats announced they had enough votes on their own to block passage.
Ultimately, the bill did not pass by a margin of 50-49, well short of the 60 votes required.
Any other sticking points?
Take your pick:
- a comprehensive immigration deal that includes Daca protections (for Democrats)
- border security, immigration reform and funding for a border wall (for Mr Trump)
- increasing military spending (for defence hawks)
The presences (or absence) of any of the above could all have been reasons for legislators to go from yes to no.
So what’s going to happen?
Many federal agencies will close down and it is likely federal employees will be forced to take a leave of absence.
Emergency services such as national security and air traffic control will still continue.
US Defence Secretary Jim Mattis said that over 50% of his department would not go to work, and some maintenance, training and intelligence operations would come to a halt.
National parks and monuments could face closure, which provoked an angry public reaction during the last shutdown in 2013.
Prior to the vote, the Trump administration was reportedly making contingency plans to keep the national parks running if no deal is reached.
Visa and passport processing could also be delayed.