International bonds worth it?

[The 585]

This has probably been asked before, but is adding international bonds to portfolio worth it?

My current portfolio is 80/20, with the stocks portion mirroring total world cap (VTWAX). For the 20% bonds, it's all in US total bond (VBTLX)... however for a truly international porfolio I'd love to have that 20% in or mirroring BNDW (Total World Bond). Sadly there's no mutual fund equivalent of BNDW so I'd have to do a split of VBTLX and VTABX unless I convert all my shares to ETF -- this would be in an IRA where most of my core holdings are.

Would I be over complicating things by doing this, or does it have sense?

[MustacheAndaHalf]

Vanguard includes international bonds in their "target retirement funds", so that's a strong vote to include it.  Personally, I avoid international bonds because they haven't offered great yield in the past.
https://investor.vanguard.com/etf/profile/BND
https://investor.vanguard.com/etf/profile/BNDX

Total (U.S.) Bond Market ETF (BND) offers 1.46% SEC yield at a 0.035% expense ratio.  Meanwhile Total International Bond ETF offers 0.60% SEC yield at a 0.08% expense ratio.  BND holds 72% in "AA" bonds or better, while BNDX holds 48%... so BND wins there, too.  ​So you get worse yield, with lower quality bonds, while paying a higher expense ratio!

If bond quality was the issue, there's Vanguard Intermediate-Term Treasury ETF (VGIT), which invests 100% in U.S. Treasury bonds of 1-10 year duration.  That ETF has a 1.09% yield for an expense ratio of 0.05% (U.S. government bonds are considered the safest investment in the world, above "AAA" grade bonds).
https://investor.vanguard.com/etf/profile/overview/vgit

Each of the measures I listed favors U.S. bonds.  I didn't list duration because it's more complicated, but duration was shorter (less risk) with VGIT and BND.  Based on what I looked up today, my view is unchanged - I plan on avoiding international bonds.