On a quiet, leafy street in northwest Washington DC sits a shabby decaying house with a gold plaque on its door. The grass in the garden hasn't been cut for weeks, garbage is strewn in the backyard, the paint around the windows is cracked and peeling. The plaque sign reads 'Royal Nepalese Embassy'.

I stumbled upon this sad little scene walking back from the nearby National Cathedral to my temporary home downtown. As I walked down the street towards the house, it was obvious that something was wrong. A shaggy fringe of weeds and long grass protruded onto the sidewalk. Silence reigned behind the untrimmed hedge. Windows were shuttered. All around are well kept family homes with childrens' swing sets and toys on the lawn. It was a sunny Saturday afternoon, so parents and kids were out enjoying themselves.

Poor countries face big financial challenges maintaining a diplomatic presence in expensive places, and Washington DC is certainly one of them. The salary of an ambassador from a small, developing country would not tempt an American factory worker or landscape gardener. Just paying the monthly bills is often a challenge.

In Islamabad, where I lived for four years in the 1990s, diplomatic staff from African countries often supplemented their paltry recompense by selling contraband whisky to thirsty foreigners like me who didn't have official permission to buy alcohol in the Islamic republic. A prominent South Asian ambassador in London once had to sell valuable paintings inside his embassy to pay for some roof repairs. His successor later accused him of stealing rare works of art.

I have a lot of sympathy for people in this position, but the state of the Nepal ambassador's residence in Washington is a disgrace. It reflects badly on a country far away that needs more friends and support, not the contempt of strangers. The American capital is one of Nepal's two most important diplomatic postings (the other is New Delhi) and keeping up appearances is part of the job.

There are excuses to be made. His excellency, the late Jaya Pratap Rana, passed on a few months ago after a long illness which meant he was never really able to take up his post. He was well and lively when I met him at a conference of Nepalis in America two years ago. His successor has been appointed but evidently has not yet arrived, or hasn't gotten around to issuing orders for maintenance.

Nonetheless, it all begs the question: what is the staff of the Royal Nepali Embassy doing on a day-to-day basis? They have, I'm sure, the usual duties of the diplomat: networking, reading newspapers, searching for American investment in Nepal. I'm sure they could spare a little time to trim the grass around the ambassador's residence and pick up some of the rubbish in the backyard.

Diplomacy, ultimately, is about appearances, and in Washignton that is being allowed to slip badly. It's been a long time since a happy crowd of power brokers and influential Americans toasted the kingdom in the garden while succulent sekuwa sizzled on the barbecue.

It's hard to avoid linking the decline of the house and the nation it represents. Nepal's elite has been absent without leave, or neglectful, or simply not paying attention. The garden (the country's hinterland) is unkempt, dangerous and depopulated. The house (the state) is a sad wreck, dry rot in all of the beams and corruption from the attic to the basement.

If someone, anyone, doesn't do something soon, the whole structure could collapse and make things even worse in the neighbourhood. And I'm not talking about a house here.