Why US citizenship isn't required to be drafted into war as attacks on Iran continue

As Donald Trump's war on Iran continues, rumors are circulating about the possibility of the US introducing a draft in the case of a war on the ground.

This is just a rumor at the moment, and while the US does still have a conscription system for the armed forces it hasn't put a draft into force for decades.

The last time the US began to draft fit young men into the armed forces was during the Vietnam War.

While there hasn't been a draft called since the Vietnam War, Trump's war with Iran has sparked fears that a draft will once again be initiated.

In the US, people are still required to sign on with the Selective Service System, but it's not just US citizens who have to sign on.

So how exactly do the rules work?

The US still has a draft in place, though it hasn't activated in decades (ALI AL-SAADI/AFP via Getty Images)

Well as it currently stands, men aged between 18 and 25 have to register with the Selective Service System, effectively putting your name in the hat to be drafted in the case of a national emergency.

If someone who is required to sign on fails to do so then they could face felony charges.

But who exactly does have to sign on with the Selective Service System?

Well, believe it or not it's not just US citizens between 18 and 25 who are required to register - the rules apply to all men in that age group, including immigrants, refugees, and asylum seekers.

The question 'Are undocumented males required to register?' appears in the frequently asked questions section on the Selective Service System website.

It says: “Yes. All undocumented males 18 through 25 years of age, other than those admitted on non-immigrant visas, must register, whether or not they have a green card.”

Men aged 18-25 have to register (Chip Somodevilla/Getty Images)

The site added: “Registration with Selective Service must continue as a key component of our national security strategy.”

However, there some things which would make you eligible for an exemption to the draft, though you do still have to register.

For example, if you're a member of the clergy or are a male student preparing to take on a minstry.

There is also the exception for sole surviving sons, where every brother except one has died, as well as 'only sons'.

Other exemptions include men who are visiting the US on certain visas such as student, diplomatic, visitor, or tourist - so you're not going to get drafted if you're visiting the US on your holidays or on a student exchange program.

You're also obviously exempt if you're already on active duty, as well as if you're a cadet or midshipman at a US service academy, and some military colleges are also exempt.